A TREATISE ON ECHINOCOCCUS DISEASE* 
INCORPORATING THE REPORT OF THE SECOND CASE OF THE DISEASE 
TO BE REVEALED IN THE APE, CYNOCEPHALUS PORCARIUS 
By E. B. HELLER, M.D. 
Kansas City 
INTRODUCTION 
One adds to the literature of echinococcus disease with a certain 
amount of trepidation, because the disease is relatively rare in these 
United States. Yet, paradoxically, there scarcely passes a month 
without a report in one of the current periodicals of an incidence 
of the disease. It has occurred to me that there does not exist in 
the English language a monograph of recent issue dealing with the 
diseases in all its phases. This, together with the fact that I have 
recently encountered (and reported) the disease in the post-mortem 
examination of an ape from the Kansas City Zoological Park,1 stimu- 
lates me to the present effort. Inasmuch as I propose to review the sub- 
ject in all its phases, I may be pardoned for including illustrations 
and descriptions of my case in conjunction with reviews and illustra- 
tions of cases in the human subject, collected from the literature. 
Medical zoology and its relation to public health problems have 
received considerable attention of late years, both at home and 
abroad: Witness such pleas as that of Hegner,2 a recent editorial 
in the Journal of the American Medical Association? the devotion 
of an entire week of the Second National Medical Congress of 
Argentina to a symposium on echinococcus disease from every 
possible standpoint, and the establishment at Cambridge University 
of an Institute of Animal Pathology to better coordinate the depart- 
ments of medicine and agriculture in their fight against disease. If 
not the most important subject for study, echinococcus disease cer- 
* The complete text of the Alvarenga Prize Essay of the College of Physi- 
cians of Philadelphia, awarded October 3, 1923, some previously published 
illustrations being omitted. 
253 254 
INTERNATIONAL CLINICS 
tainly furnishes one of the most interesting investigations with about 
equal significance to the lower animal world and the human. 
When I say that the disease is relatively rare in the United 
States I am fully aware of the fact that many, many cases are never 
reported at all, or are reported before local medical societies and 
never get into the current periodicals. In talking with a number 
of busy surgeons of western Missouri and eastern Kansas, I was 
unable to find one who had not had one or more cases to deal with 
in recent years. 
I am greatly indebted to Mr. Miles Standish, of Kansas City, 
for the interest and skill he has demonstrated in photographing my 
specimens and in preparing the prints. I am also indebted to Dr. 
Samuel Voegelin for the preparation of microscopic sections of the 
various organs, and for the interest he has shown in their study. 
Mr. 1ST. T. Clark, in charge of the Kansas City Zoological Park, 
intensely interested in the welfare of his proteges, has stimulated 
the interest of myself and others in the diseases occurring among 
the wild, and deserves all manner of praise from the people of our 
home city. 
I wish also to express my greatest appreciation to Dr. C. E. 
Corlette, of Sydney, Australia ; to Dr. F. Ware, of the Civil Veter- 
inary Department, Madras, and Major R. Knowles, of the Indian 
Medical Service, Calcutta, for the courteous and thorough manner 
in which they replied to my inquiries. 
DEFINITION 
Echinococcus disease is an infection or infestation, visceral, 
somatic or both, with the larval Echinococcus granulosus. Man and 
about forty other mammals act as intermediate hosts, harboring the 
larval cycle of Taenia echinococcus, or the “ dog tape-worm.” As the 
latter name implies, the adult stage is completed in the small intes- 
tines of the dog or some other member of the Canidse, being the 
intestinal infection (or infestation) in contradistinction to the 
somatic infection or larval cycle, which seems to require for its 
development tissues of an herbivorous or omnivorous host. ECHINOCOCCUS DISEASE 
255 
SYNONYMY 4 
Genus Echinococcus Rudolphi, 1801. 
1782. Hydatis Goeze, 1782a., 192; very doubtful whether this 
is used in a generic sense in synonymy. 
1801. Echinococcus Rudolphi, 1801, 52-53; includes Tcenia 
multiceps (type of multiceps, 1782, and polycephalus, 
1800) and Tcenia visceralis socialis granulosa Goeze, 1782, 
hence it is a deliberate renaming of a genus for which two 
names were already available, but Rudolphi definitely 
mentions Die hornigen Blasenwormer (namely granulosa) 
as basis of Echinococcus, hence this is the type species; 
see also Rudolphi, 1802, 204. 
1804. Acephalocystis Laennec, 1804, 132, 134-135; 1812, 96- 
123, 130-155, 170-173; type apparently Echinococcus 
granulosus, by inclusion. 
1819. Liococcus Bremser, 1819a, 249; type Echinococcus 
homnnis, genus not adopted by Bremser, 1819a. 
1819. Splanciinococcus Bremser, 1819a, 249; Echinococcus 
renamed, hence same type. 
1821. Acepiialocystus Laennec of Merat, 1831, 229; for 
Acephalocystis, 1804, hence same type. 
1829. Acephalocistis Cruveilhier, 1829a, 198; for Acephalo- 
cystis, 1804, hence same type. 
1829. ?? Acrostoma Lesauvage, 1829, 433-438; hence only type 
species. A. amnii; probably pathological structure of 
amnion. 
1844. ? Astoma Goodsir, 1844d, 282; only hence type species 
A. acephalocystis Goodsir. 
1844. ? Diskostoma Goodsir in Gairdner, 1844a, 276; only hence 
type species D. acephalocystis Goodsir. 
1844. ? Sphaeeidion Goodsir; not accessible; see Gervais, 1847a, 
92. 
1856. Echinokokkus Buhl, 1856a, 429; for Echinococcus, hence 
same type. 256 
INTERNATIONAL CLINICS 
1858. Echinococcifer Weinland, 1858, 52, 61, 85; type Tcenia 
echinococcus. 
1894. ? Discostoma Braun, 1894a, 982; for Diskostoma Goodsir, 
1844, hence same type. 
It is thought by some that Echinococcus disease was known to 
Hippocrates. Hosier and Peiper in Nothnagel’s “ System of 
Medicine ” make the following quotation from his writings: 
Quibus jecur aqua repletum in omentum eruperit, Us ventu aqua 
impletur ac intereunt* 
The earliest mention of the disease by modern writers is by 
Huy sell in 1721, when he described a condition which was undoubt- 
edly Echinococcus multilocularis, as “ Colloid cancer.” Goeze, in 
1782, was the first to use the term Hydatis to describe the condition 
although Stiles 4 doubts whether he used the term in a generic sense. 
The work of Batsch (1786), and of Rudolphi (1801-1805) 
established the type species Echinococcus granulosus, which termin- 
ology is largely used to-day. Considerable work was done by German 
investigators during the nineteenth century, and notable is the work 
of Leuckart, Kmchenmeister and Virchow. It was Kiichenmeister 
who, in 1851, demonstrated by feeding experiments that the cysts 
were only the larvae of tape-worms, and that for a complete life 
cycle, two hosts were necessary. 
The older writers frequently described the condition which was 
undoubtedly echinococcus disease, as an “ alveolar colloid cancer.” 
Sir Astley Cooper, in 1837, in describing cystic disease of the female 
breast, referred to it as “ hydatid disease.” Much confusion exists 
even up to the present, as to the proper terminology and classifica- 
tion. M. C. Hall, of the Bureau of Animal Industry of the United 
States Department of Agriculture, has done much to clear up the 
situation by compiling a very complete monograph dealing with 
adult taenioid cestodes of domestic carnivores of Horth America.5 
The multilocular (also called alveolar) hydatid or echinococcus 
was first recognized and described by Virchow in 1855.6 In 1888 
HISTORY OF THE PARASITE 
* “ When the liver is filled with water and hursts into the epiploon, in this 
case the belly is filled with water and the patient dies.” Fig. I, 
KEY TO MAP 
Shaded areas 
represent 
regions from 
———which large 
numbers of cases have 
been reported. Solid 
black represents areas 
in which Echinoc.ocous 
—Ptaeaso 14} unagnifl'. 
Map showing distribution of echinococcus disease throughout the world 257 
ECHINOCOCCUS DISEASE 
he established the fact that echinococcus disease of the liver and of 
bone are the same disease. He, moreover, recognized the fact that 
echinococcus of the multilocular and that of the cystic type are the 
same parasite under different conditions of life.7 
Since 1901, many authors have aligned themselves with 
Melnikow-Raswedenkow,8 who stated it as his conviction that 
Echinococcus alveolaris occupied an intermediate position between 
Cestodes (tape-worms) and Trematodes (flukes), because of its 
power to produce amoeboid embryos in loco. He also insisted that 
two species of the parasite were required to produce the two forms 
of the disease (cystic and alveolar). 
The best opinion to-day, however, is in support of Virchow’s 
early contention, e.g., that but one species, commonly known as 
Tccnia echinococcus, is the cause of the disease in its various mani- 
festations. Stiles 9 admits only one species, as does Corlette.10 The 
views of the latter author have been ably expressed, and his work 
stands at present as one of the best, if not the best, with reference to 
the etiology and pathology of echinococcus disease. 
GEOGRAPHIC DISTRIBUTION 
Echinococcus disease is cosmopolitan, that is to say, it is common 
to all the world, with a special predilection for the Temporate Zone, 
and a mild abhorrence for the tropics. (See map, Fig. 1.) Stiles 
says that Iceland is recognized as the classical Echinococcus Land. 
The disease is evidently of long standing there, for reports give the 
incidence as one to every thirty of the population (Galliot), and 
Krabbe reports 25 per cent, of the dogs infested with the Teenia. 
Iceland was settled bv the Norsemen in 874. In view of the fact that 
Hippocrates is supposed to have known the disease, it would be 
interesting to determine whether or not the imported dogs and sheep 
brought the disease to the island in those early times. It would 
be a still more interesting study to seek out the original nidus from 
which the disease has spread throughout Europe, and via, the trade- 
routes, through the medium of dogs, sheep, and other hosts, to North 
and South America, India, Australia, and South Africa. Australia 
and Argentina vie with Iceland for greatest incidence of the disease. 258 
INTERNATIONAL CLINICS 
In the province of Victoria., Australia, records show that one out 
of every one hundred seventy-five (175) hospital patients is suffer- 
ing with the affliction, while three in every thousand die of the 
disease. The Mt. Gambier Hospital records one echinococcus patient 
to every sixty-five admissions for all complaints. Corlette and 
others have called attention to the fact that human infection is 
relatively uncommon in the more tropical parts of Australia, whereas 
the incidence in animals is not affected. In a personal communica- 
tion (January 28, 1923) he modifies his statement by adding that 
“....the population of tropical Australia is at the same time so 
scanty, and also much of the occupied country is cool tableland.” 
This latter observation is interesting in view of reports from 
India, where echinococcus disease has been found in 70 per cent, 
of the cattle (Friedberger and Frdhner), whereas the disease is 
rarely reported for human beings in India. A recent personal 
communication from Ware,11 of the Civil Veterinary Department, 
Madras, India, confirms the figures of Friedberger and Frohner 
“ for the south of India.” An interesting fact is that the workers in 
animal pathology have never recovered the Taenia from the native 
dogs of Madras, nor have they been able to infect dogs, although 
Ware states that they have made the attempt four times by feeding 
hydatids. If Ochsner’s theory of cancer-infection is tenable, the 
methods of cooking food in India, besides warding off cancer of the 
alimentary canal, would incidentally safeguard the population from 
echinococcus disease. 
For a similar reason, it would seem that the whole of southern 
Asia is protected. No considerable number of cases has been 
reported, yet with the advance of civilization in these countries, we 
may look for a penetration of the disease. 
As has been stated, the disease is common in Europe, especially 
in Silesia and the mountainous districts of Austria. During the 
latter half of the past century, much of the work on hydatid disease 
was done in Germany because abundant material was available, and 
the disease had to be controlled for economic reasons. At one time 
the slaughter-house statistics gave the incidence of the disease as 
10.39 per cent, for cattle, 9.83 per cent, for sheep, and 6.47 per ECHINOCOCCUS DISEASE 
259 
cent, for hogs. Madelung in 1026 autopsies (human), at Rostock 
from 1861 to 1883, found the hydatids in twenty-five cases. 
Although comparatively few cases are reported from Greece, 
there must be a large morbidity from echinococcus disease inasmuch 
as Greek emigrants rank high among those suffering with the disease 
in America. Within a year (1921-1922) three young Greeks were 
operated on in various cities for advanced echinococcosis, to wit, 
a cyst of the liver by Da Costa, of Philadelphia; one of the right 
kidney by Kretschmer, of Chicago; and a case with two cysts of the 
liver by A. J. Welsh, of Kansas City. Greeks ranked second in 
number among the eighty-seven cases in Korth America collected by 
Magath.12 The tendency of these people to operate restaurants and 
fruit stands would render them dangerous to the community were 
the disease more readily transmitted. (See table, page 261.) 
In Korth America cases have been reported from every section, 
for the most part- north of the thirtieth parallel. The disease is said 
to be endemic in some sections of Canada, notably Manitoba, which 
province is inhabited by numerous Icelanders. Ferguson has operated 
upon many of these people for the disease (Osier). Epidemics have 
occurred among hogs in Virginia, Wisconsin, Arkansas and Oklahoma. 
At least in the case of Virginia, Johnston and Willis13 have shown a 
direct connection between the epidemic in the hogs, and a subsequent 
epidemic among human beings. 
At one abattoir in Kansas City, in 1904, infection in hogs was 
reported as one per cent. (Stiles). Uo doubt indigenous cases have 
occurred in man which have not been recognized. All of the sur- 
geons of experience, in Kansas City, have had one or more cases of the 
disease come to them from adjacent territory. Johnston and Willis 
state that only 250 cases were reported in the United States up to 
1913. Including cases reported in animals, the number far exceeds 
this figure for the subsequent period. Some of our large hospitals 
and clinics report numbers of cases—thus, at the Massachusetts 
General Hospital, Davis and Balboni14 recently analysed the records 
of twenty-nine cases (1875-1916), while there have been twenty- 
five cases at the Mayo Clinic in as many years (Magath12). 
Corlette15 says that he has “ always found it puzzling to account 
for the scarcity of hydatid disease in the United States.” In his 260 
INTEENATIONAL CLINICS 
paper (loc. cit.) he alludes to another puzzle its rarity among 
the human inhabitants of India while at the same time there is 
ample evidence that it is extremely common in the domestic farm 
animals of that country. The immunity of man in India is therefore 
not due to absence of the echinococcus from the country, nor can 
it be due to sanitary precautions on the part of the native, who does 
not in the least object to the use of fecalized water, patronized by 
dogs.” This last statement would cast some doubt about Ochsner’s 
statistics and theory. 
The disease is so prevalent in the temperate portions of South 
America, that considerable research has been stimulated. For in- 
stance, some of the first work on the complement-fixation test as 
applied in the diagnosis of hydatid disease was done by Apphatie 
and Lorentz116 in Argentina, as far back as 1908. From October 
1 to 8, 1922, the Second National Medical Congress of Argentina 
devoted all of its time to a discussion of the disease. The city and 
province of Buenos Aires had 89 per cent, of the 2740 cases of the 
disease treated surgically in the, past eleven years in Argentina. The 
proceedings of this convention would be well worth reading to anyone 
interested or to one who doubts the positive danger from the disease. 
In 1910, 5 per cent, of the sheep and cattle were found infected. Now, 
30 per cent, of the sheep and 15 per cent, of the cattle are infected. 
That the disease is present in South Africa, is evident from case 
reports, and from the fact that the disease has even penetrated the 
neighboring wilds. My case is the second reported in apes from the 
wilds of South Africa, the first having* been reported by Nicoll,17 of 
Lister Institute, London, in 1918, in an animal of the same family 
and genus (Cynocephalus porcarius) as my own. This is interesting 
in view of the fact that Weidman,18 in a personal communication, 
states that in more than 5000 autopsies performed at the Philadelphia 
Zoological Gardens in the last fifteen years, the disease has not been 
met with in monkeys. On the other hand, he states that they have met 
with a few cases of Cysticercus tenuicollis in monkeys, and that it 
appears to be rather common in the wild. 
According to Rivas19 Tccnia echinococcus multil ocular is is not 
reported for Iceland and Australia. Corlette, however, with his 
wide experience with the disease in Australia, maintains that both ECHINOCOCCUS DISEASE 
261 
the multilocular and the granulosus types are present, that they 
are nothing more than the same parasite under different con- 
ditions of life, and that the former is the result of intensive exog- 
enous budding, while the latter is the result of endogenous budding, 
or at least of failure to produce daughter-cysts by exogenous budding 
from the onchosphere. Further, he shows that both varieties may 
occur in the same host, and in the same echinococcus cyst. It may 
therefore be assumed that equally experienced investigators in Ice- 
land would find similar conditions prevailing there. One is forced 
to agree with Corlette after a review of the literature, and in doing 
so subscribe to the contentions of Virchow, who, in 1844, stated it 
Table Showing the Nativity of Patients with Echinococcus Disease Reported 
from North America (Magath) 
Before 1902 
Since 1902 
(Lyon-Magath) 
(Magath) 
Iceland 
58 
5 
Germany 
23 
9 
Italy 
19 
19 
England 
14 
3 
Ireland 
3 
4 
France 
3 
0 
Kussia 
4 
6 
Syria 
2 
1 
Argentina 
1 
2 
Azores 
1 
0 
Austria 
1 
2 
Denmark 
1 
0 
Japan 
1 
0 
Mexico 
1 
0 
Sweden 
1 
1 
United States 
5 
6 
Canada 
2 
2 
Negro (nativity unknown) ... 
6 
0 
Greece 
0 
17 
Turkey 
0 
1 
Armenia 
0 
5 
Eoumania 
0 
1 
Spain 
0 
1 
Albania 
0 
1 
Wales 
0 
1 
Other foreigners 
3 
0 
149 
87 262 
INTERNATIONAL CLINICS 
Table Shotting the Organs Affected in Cases Reported After 1902 (Magatli) 
Organs 
Cases 
69 
Peritoneum 
10 
Lungs 
4 
Kidneys 
4 
Omentum 
4 
Spleen 
2 
Retroperitoneal 
2 
Spinal cord 
1 
Brain 
1 
Abdominal wall 
1 
Gall-bladder 
1 
Common bile-duct 
1 
Uterus 
1 
Neck 
1 
Tibia 
1 
Pleura 
1 
104 
as his belief that both types of cyst formation were manifestations of 
the same parasite under different conditions of life. Thus, compres- 
sion in the case of bone has the same effect, but to a greater extent, 
as has the pressure of Gflisson’s capsule on the individuals in the 
liver, etc. 
According to M. Simon,20 echinococcus disease is endemic in man 
in Sweden. It is also quite prevalent in Norway. 
ZOOLOGICAL, DISTRIBUTION 
The adult worm, Taenia echinococcus, is found to inhabit the 
upper small intestine of the dog, wolf, and other Canidce, the most 
common hosts being: Canis familiaris, C. lupus, C. aureus, C. 
dingo, C. mesomelas, Felis catus domestica, F. concolor. The para- 
site prefers an alkaline medium, and therefore is seldom found 
in the first portions of the duodenum of the primary host, but in the 
terminal portion, and in the upper jejunum. Here large numbers 
are often found adhering to the villse. Their small size renders 
them difficult of detection unless they are especially looked for. 
The larval stage occurs in practically every organ and tissue of 
the secondary host. The liver is the organ involved in more than 
50 per cent, of cases, either alone or coincident with involvement of ECHINOCOCCUS DISEASE 
263 
other organs. The lungs are involved in about 10 per cent, of 
cases; the kidneys, 10 per cent.; muscles, subcutaneous tissues and 
bone in 10 per cent.; the central nervous system, 5 per cent., and the 
spleen and other tissues in 15 per cent. The embryos seem to 
prefer loose cellular tissue, and in the case of the large vascular 
organs as the liver and spleen, they develop close to the surface, 
in the subserosa, and as they grow, present about 20 per cent, of 
their contour beyond the surface of the invaded organ. 
The following list includes all the principal secondary hosts: 
Homo sapiens, Bos taurus, Ovis aries, Capra hircus, Sus scrofa 
domestica, Sus scrofa, Pithecus species (Simia cynomolgus), 
Pithicus silenus (Simia silenus), Simia sylvanus (Simia inuus), 
Cynoceplialus porcarius, Ovis ammon, Camelus hactrianus, C. drome- 
darius, Giraffa species (Camelopardalis giraffa), Tetraceros quad- 
ricornis, Alces alces, Equus caballus, E. zebra, E. asinus, Tapirus 
indicus, Canis familiaris, Felis catus domestica, F. pardus, Macropus 
major, Sciurus vulgaris, Mungos ichneumon (Herpestes ichneumon), 
Simia sylvanus (Inuus ecaudatus), Macropus giganteus, Ovis argali, 
Tapirus americanus, and Oryctolagus cuniculus (Lepus cuniculus). 
It will be noted from the above that several of the animals harbor 
the parasite in both the larval and the adult cycles, in fact the same 
animal may on occasion be the host of both cycles. More extensive 
research will probably prove some of the above animals to be the 
victims of a cysticercosis, the difference between the various bladder- 
worms being but poorly understood by some of the older investigators. 
THE PARASITE 
Tcenia echinococcus, Siebold, 1853. (Type, Vermes; class, 
Plathelmintes; order, Cestodes; family, Tsenia; group, Taenia, vesic- 
ular oiv cystica of Leuckart.) 
The best authorities, as has been said, at the present time admit 
only one species, Taenia echinococcus (Zeder, 1803; Siebold, 1853). 
If, as suggested by Weinland, the species be placed in a distinct 
genus, the name would be Echinococcus granulosus (Batsch, 1786; 
Zeder, 1803; Kudolphi, 1805). For the sake of simplicity in 
explaining the pathology as presented in various organs of various 264 
INTERNATIONAL, CLINICS 
hosts, in various parts of the world, it is probably best to divide the 
genus into two species as suggested by Rivas:19 
(a) Echinococcus granulosus, or Taenia echinococcus unilocu- 
lar is. 
(b) Echinococcus multilocularis, or T. echinococcus multilocu- 
laris. 
Taenia echinococcus is one of the smallest tape-worms known, 
being four to five millimetres long. The head is very small, sub- 
globular, and about 300 microns in diameter. The rostellum is 
rather prominent, and is armed with a double row of hooklets, 28 
to 50 in number. The large hooks are 22 to 30 microns in length, 
and have a blade of very slight curvature, which tends to lie in 
a prolongation of the longitudinal axis of the handle, and which is 
very thick at the base. The handle is straight, short and thick, with 
dorsal and ventral swellings in the median portion. The guard is 
very short, is rounded, and forms a hemispherical protuberance. 
The smaller hooks are 18 to 22 microns long, with a very short and 
slightly curved blade which lies in a prolongation of the longitudinal 
axis of the handle; the handle is comparatively long and narrow with 
a prominent dorsal swelling near the middle, which causes a tapering 
to the distal extremity. The guard is relatively quite large and oval 
in outline. The suckers are on the average 130 microns in diameter 
and are set well back from the rostellum. The neck tapers posterior 
of the suckers, and then gradually expands to meet the anterior 
margin of the first segment. The first segment is almost square, 
being about 240 to 260 microns long and wide, and is devoid of 
generative apparatus. The second segment is about twice as broad 
in its posterior portion as the first segment, and is about four times 
as long. It contains generative apparatus. The third segment is 
gravid, and comprises about one-half the length of the entire strobila, 
being about 2 millimetres long. The maximum width is attained 
just caudad of the genital pore, being 600 microns. The longitudinal 
excretory canals are visible and often contain calcareous corpuscles. 
Male Genitalia.—There are about 50 testes to each of the mature 
segments. They are 70 microns in diameter, and are situated for 
the most part in the ends of the segment and opposite the genital 265 
ECHINOCOCCUS DISEASE 
pore. The vas deferens originates near the median line of the 
segment on the poral side of the median stem of the uterus, and 
anterior of the ovary. There are found several wide coils before 
the distal portion emerges into the genital pouch, which latter is 
about 500 microns long and extends into the segment almost to the 
median line. 
Female Genitalia.—The ovary is horse-shoe shaped with a 
median isthmus narrower than the ends, and the concavity posterior 
is submedian in position and about half-way between the plane of 
the genital pore, and the posterior border of the segment. The 
vitellarium is situated near to the posterior border of the segment 
and consists of a dorsal and a ventral lobe, which lie one above the 
other, and are formed of two portions each with its own duct. The 
shell-gland is spherical to oval. The ovaries, vitellarium and uterus 
have the common openings of their tubes within the shell-gland. 
The vagina has a large, elongate, setose dilation about 50 microns 
in diameter near the genital pore and bends at an obtuse angle 
mesad of this to extend posteriorly and mesially to a receptaculum 
seminis about 14 microns in diameter. The uterus develops com- 
paratively late, forming a median stem and lateral enlargements, the 
outlines of these later becoming quite distinct. The eggs are 32 to 
36 microns by 25 to 30 microns in diameter (Hall). 
The ova of the parasite are discharged with the fseces of the 
primary host, and are taken into the alimentary canal of one of the 
secondary hosts with food or water. Here the six-hooked embryos 
escape from the shell and burrow through the wall of the intestine— 
many finding their way into the portal system or lymphatics; and 
doubtless some migrate up the biliary passages into the liver and 
gall-bladder. Johnston and Willis 13 contend that eggs which 
become attached to dust particles, and which are inhaled by a suit- 
able host, develop into cysts in the lungs of that individual. I 
have been unable to find any other writers on the subject of echino- 
coccus disease who give air-borne infection of the lungs any place. 
ISTormal mucous membrane of the respiratory tract would hardly 
he abie to furnish the necessary solvents of the shell of the embryo, 
LIFE CYCLE OF THE PARASITE AND MODES OF INFECTION 266 
INTERNATIONAL CLINICS 
which must precede its liberation. In spite of the fact that there is 
no authentic record of infection of the lungs direct from contami- 
nated air, such an event might possibly occur, in view of the fact 
that Hutchings 21 and others have demonstrated the development 
of hydatid cysts following the direct implantation (on denuded sur- 
faces) of the ovum of Tcenia echinococcus. That the scolices and 
brood-capsules are capable of developing cysts when sown upon 
suitable soil has been abundantly shown in cases of rupture of 
mother-cysts either at surgical operations or spontaneously—the 
scolices being liberated into the peritoneal cavity or upon the raw 
edges of the wound—developing cysts where they have become 
attached. Then, too, the reported cases of echinococcus cysts, pri- 
mary of the lung, with no other apparent visceral involvement, lend 
force to the argument in favor of air-borne infection. 
When the disease is widespread in the body of the secondary or 
intermediate host, the term echinococcosis is applicable, and the 
process is known as liydatidization. Given embryos which have been 
liberated from their shells by the solvent action of the digestive 
juices of the secondary host, the following tabulation represents 
some of the possible eventualities: 
liydatidization.— (1) Direct or primary implantation of embryos 
as emboli, in the various organs of the body, i.e., liver, spleen, heart, 
lungs. (2) Indirect, or secondary implantation of scolices or brood- 
capsules as emboli in various tissues of the secondary host, (a) 
Inoculation of the peritoneal cavity, pleural cavity, etc., by rupture 
into them of a fertile cyst, brood-capsules being sown upon the 
serosa. (6) Embolization of lungs, heart, brain and other extra- 
abdominal organs by fertile cysts or scolices from a primary or 
secondary colony in an abdominal organ or in bone, (c) Propa- 
gation, by exogenous budding, or growth of individuals of a colony 
in one organ, into an adjacent organ or tissue. (3) Infection of 
another individual through the ingestion, implantation, or inhala- 
tion (?) of fertile cysts or viable scolices. 
The adult stage is not necessary for the transmission of the 
disease, epidemics having been reported in man due to the eating 
of infected organs of sheep or hogs, and in hogs, due to the eating 
of infected organs of sheep, and so on. !? 
S 
JnD 
DIAGRAMS OF LARVAL CYCLE;ECHINOCOCCUS GRANULOSUS. 
(AFTER MOSLER and PEIPER,STEWART,LEUKART,ZIEGLER,and LENDON), 
1. Ovum, about O.OI mm. in diameter, showing six-hooked embryo. 
2. Embryo free from its shell. 
3. Cyst differentiated into outer laminated layer and parenchyma. 
4. Aoephalocyst stage. An outer laminated layer and an inner paren- 
chymatous layer, both now vascular, enclosing fluid. 
5. Showing development of Brood-capsules. 
6. Showing in some detail, a cross-section of the cyst-membrane, 
also the parenchyma containing one complete brood capsule, 
with developing Scolex or tape-worm head. 
7. Developing daughter cysts, showing one which might easily bud 
externally. 
8. Daughter and grand-daughter cysts. 
9. Mass of small Daughter-cysts,-mother-oyst having disappeardd. 
This type is most common in bone. 
10. Shrinkage of mother cyst, causing parasitic wall to be folded, 
and between these folds is vascular fibrous tissue belonging 
to the adventitious cyst, the whole forming a semi-solid or 
solid mass, having a honey-comb-like foliated appearance on 
section, compared to the heart of a cabbage, or resembling 
colloid cancer. 
11. Scolices, with rostellum and hooklets protruded or retracted(a) 
like a vorticella,-just visible as specks when the fluid is 
held up to the light,-measuring about 0.3 mm. 
12. Section of echinococcus membrane with curled in edges. ECHINOCOCCUS DISEASE 
267 
Although most embryos enter the portal system from the villse 
of the upper small intestine, there is ample evidence that some enter 
the lymphatics, and still others enter the peritoneal cavity by 
traversing the entire thickness of the wall of the gut. Then, too, 
there is proof that some embryos enter the ampulla of Vater, and 
proceed upward into the liver and gall-bladder. Once having come 
to rest in a venous, biliary, arterial, or lymphatic radical, the hooks 
disappear, and the embryo develops into the larval stage, a bladder- 
worm (Fig. 2). 
The growth is very slow, Leuckart in his experiments on swine, 
having demonstrated that it requires five months for a, cyst to become 
15 to 20 millimetres in diameter. If the cyst or cysts are not in 
such position as to interfere with vital functions, the growth is often 
very great, cysts the size of a child’s head having been reported. 
The bladder-worm is called an echinococcus or hydatid, and is 
characterized by the development of two layers, an outer laminated 
layer or cuticular membrane, and an inner, finely granular layer, 
the parenchyma of the cyst. The outermost covering of the cyst is 
usually fibrous tissue derived from the invaded organ. The wall 
of the cyst is normally pearly white, and fairly tough. It is chemi- 
cally described as chitin, or a substance between chitin and the 
proteins (Hammerstein). 
When the cyst attains the size of two centimetres in diameter, 
or more, conditions of life being favorable, daughter-cysts develop 
from the parenchyma or internal germinal membrane (Fig. 2). 
These may project into the motlier-cyst where they appear as dot- 
like bodies, or they may project outside the cyst and there form 
external daughter-cysts. The former process is called endogenous 
budding, and the latter, exogenous budding. Both varieties may 
occur in the same cyst. The daughter-cysts grow, and in due time 
give rise to granddaughter-cysts, and so on ad infinitum. In any 
cyst of the series, brood-capsules may be formed. These latter are 
bladders which contain scolices. In many cases the entire series of 
cysts are devoid of brood-capsules, and no scolices or booklets are 
found in the contained fluid. Such a condition is usual in cysts of 
bone, and in very old cysts. When brood-capsules or the contained 
scolices are ingested by the primary host, the heads develop segments 268 
INTERNATIONAL CLINICS 
and form adult (strobilate) worms which assemble in the upper 
portion of the small intestine, and the cycle repeats itself. Leuckart 
showed that scolices fed to dogs require ten to twelve weeks to 
develop into the adult worm, and reach the gravid stage. 
pathology: organs involved 
Under this heading the disease as it manifests itself in man 
will be considered, and the disease in the primary host, which has 
been dealt with under “ zoological distribution,” will be further 
discussed under the heading of prophylaxis. The number of lesions 
depends largely upon the number of ova ingested. That is to say, 
barring accident en route, each and every ovum ingested by a 
suitable host (secondary or intermediate), should ultimately come 
to rest as, a six-hooked embryo in the terminal radicals of one of the 
organs of the body. Here the embryo’s identity is obliterated as it 
develops into the cyst containing clear fluid. 
As has been stated, no organ or tissue of the body seems to be 
exempt from the visitation of the embryo, but the liver, because of 
its position and function as recipient of the portal blood, and its 
direct communication with the duodenum, is more often involved 
than all the other organs of the body put together—over 50 per cent, 
of cases. The lungs are involved in about 20 per cent, of cases, 
the kidneys in about 10 per cent., the muscles, subcutaneous tissues 
and bone in 10 per cent., and the central nervous system in about 
5 per cent, of cases, while the spleen and the remaining tissues are 
affected in about 15 per cent, of cases. The; cysts are very prone to 
develop in the loose cellular tissue and in the subserosa. 
If growth is unobstructed, the tendency is to rupture eventually 
from the tension of the accumulated fluid, or from necrosis of a 
portion of the cyst-wall due to pressure of the daughter-cysts. An- 
other mode of termination is to cease to grow, because of pressure 
from without, or lack of nourishment, the onchosphere and all its 
contents then shrivel up, and assume a putty-like appearance, perhaps 
later becoming impregnated with calcium salts. 
When cysts are contiguous to hollow viscera, the mutual pressure 
causes an absorption or necrosis of the intervening tissue, and a 
rupture of the cyst results in an evacuation of its contents into that ECHINOCOCCUS DISEASE 
269 
viscus. Instances of such accidents will be mentioned in subsequent 
paragraphs. On the other hand, if the intervening tissue with- 
stands the pressure, other possibilities are that gases or fluids will 
osmose through the membrane and kill the parasite, or that suppu- 
ration will ensue upon the entrance of pathogenic bacteria into 
the cyst. 
Liver and Gall-bladder.—The effect of echinococcus cysts of 
these organs vary with the situation and size of the cysts. There 
may he a single cyst or there may be many cysts in a given case. 
The museum of St. Thomas’s Hospital in London contains a liver 
removed at autopsy from a sailor, which weighs twenty-five pounds 
and is thoroughly infested with echinococcus cysts. In the liver as 
in other organs of the host, the embryo invades the loose connective 
tissue in which the hepatic vessels and ducts are located. The 
liver parenchyma surrounding the cysts shows the results of irrita- 
tion, by the development of a fibrous tissue investment, and as the 
cysts increase in size, adhesions are formed to neighboring viscera 
as a result of the localized peritonitis. Both the multilocular and 
the granulosus types of the larva, are found involving the organ, 
and the two types have even been reported in the same organ. 
Taken by and large, however, the granulosus, or unilocular cystic 
form is most common in man, while the multilocular type is found 
in the lower animals. This latter fact is used by Corlette 10 as a 
very potent argument against the two-species doctrine: “ ... if 
there are two species of parasite required for the two forms of 
hydatid disease, the multilocular species must be abundantly domi- 
ciled in South Australia, even though in the human beings only 
the cystic form has seemed to find a place.” LTeisser22 in his 
observations reported the following complications of echinococcus 
disease of the liver: 
47 ruptured into lung and pleural cavity, 
46 ruptured into stomach and intestines, 
16 ruptured into the peritoneal cavity, 
15 ruptured through the abdominal wall. 
Suppuration is the most common accident, and when it occurs, 
the clinical picture changes to one of sepsis, and the cyst contents 
gradually become disintegrated and lose their identity. In addition 270 
INTERNATIONAL CLINICS 
to these complications, numbers of instances are on record of the 
rupture of cysts into the common or hepatic ducts, and even into 
the inferior vena cava. Fowler, in 1916, reported a case of cyst 
of the left lobe of the liver which ruptured and discharged its 
contents into the left hepatic duct. A case combining many of these 
features was recently reported by Major H. W. Jones 23 of a young 
private in the medical department of the United States Army, of 
Italian birth, who died some weeks after a laparotomy during which 
the diagnosis was made. There were multiple cysts of the liver, 
multiple abscesses of the liver, a right empyema communicating 
with an abscessed cyst of the liver; the common duct contained 
cyst-membrane, booklets, and one small unruptured cyst; the hepatic 
ducts also contained unruptured cysts. 
In addition there was a cyst of the spleen with considerable 
enlargement of that organ. Another interesting feature was the 
absence of eosinophilia, a frequent occurrence, yet a point which 
confirms the observations of those most conversant with the disease, 
e.g., eosinophilia is frequently absent, and whether present or absent 
is of little diagnostic aid. 
Phemister24 several years ago reported a case with cysts of 
the liver, complicated later by subphrenic abscess, pyopneumothorax, 
and hydropneumothorax. Vegas and others have reported cases of 
hydatid pyopneumocyst of the liver. A case has recently been 
reported by Shaw of a suppurating echinococcus cyst of the liver, 
with multiple abscess formation, which recovered. When the multi- 
locular type of cyst is present, the infiltration is usually very rapid, 
a feature which has led to its appellation: “Malignant hydatid.” 
In this type the liver-cells have not time to proliferate and the organ 
to undergo the usual compensatory hypertrophy, with the result 
that it is destroyed by the rapid growth of the cysts. 
Cysts found in the gall-bladder may mean primary infestation 
from the duodenum or rupture of a primary cyst of the liver into 
it or into one of the biliary ducts. Thirteen cases of hydatid cyst 
of the gall-bladder have been reported in Argentina according to 
Gutierrez.25 In several instances cysts and calculi have co-existed. 
Allende and Tobias 26 record an interesting case of intermittent 271 
ECHINOCOCCUS DISEASE 
hydrops of the gall-bladder due to pressure on the ducts of a suppu- 
rating hydatid cyst of the liver. 
Cirrhosis of the liver plus echinococcus cysts gives a distorted 
picture, at times. Thus, Taboada27 reports a case of atrophic 
cirrhosis of the liver which resembled a hypertrophic cirrhosis with 
ascites, and which was not definitely diagnosed until autopsy 
revealed a complicating hydatid cyst. The ascites required frequent 
tapping for a while, but ultimately subsided. The case was under 
observation a total of two years. 
Spleen.—Echinococcus cysts are the most common form of cysts 
of the spleen (Moynihan), and the only parasitic type reported in 
the literature to which I have access. Trinkler found the spleen 
affected in 68 of 2117 cases of the disease. As a rule other organs 
are involved as well. In my own case (Figs. 3 to 7) it was impossible 
to determine which were the older, the cysts of the liver, or those 
of the spleen. As is usually the case, the lower pole of the organ 
contained the cysts in my specimen, and the lower one projected 
over the splenic flexure of the colon. These were of the unilocular 
variety—a fact worth recording inasmuch as so few cases are 
reported for apes, and because the multilocular type is said to be 
more common in the lower animals. 
Murchison describes a case of echinococcus cyst of the spleen 
rupturing into the colon. The unilocular cyst is the type usually 
reported for the spleen in the human being. Infection of the spleen 
may be by the way of the portal or systemic circulations, probably the 
former in the vast majority of cases. In this location the cysts are 
subject to the same accidents as are cysts of the other abdominal 
organs. Like the liver, the spleen undergoes hypertrophy to com- 
pensate for the parenchyma displaced by the cyst or cysts. 
Heart.—Echinococcus cysts are not rare in this organ. The 
parasite selects the loose areolar tissue of the auriculo-ventricular 
groove, and then may bulge into the adjacent cavities. The 
cyst or colony of cysts may cause death by interfering with the 
action of the heart, or by rupturing into one of the adjacent cavities, 
from whence daughter-cysts, membrane or detritus is carried into 
the pulmonary or systemic, circulation (Bland-Sutton). H. W. 
Mills,28 of San Bernardino, California, reports an interesting case 272 
INTERNATIONAL CLINICS 
in a French woman of a hydatid cyst in the wall of the right ventricle 
near the apex, five centimetres in diameter, and with four cysts in 
the right lung. In his bibliography he enumerates no less than sixty 
authors who have reported cases of echinococcus cysts of the heart 
and pericardium. Iiis case was diagnosed at autopsy as is usually 
the case. Rarely cases are diagnosed during the life of the patient. 
One such case is recorded in the Medical Journal of Australia 
(April 9, 1921) by Martin and De Crespigny where the fluoroscope 
revealed a rounded opacity behind the sternum which pushed the 
heart to the right and which was about the size of a “ fetal head at 
term.” Exploratory puncture confirmed the diagnosis but probably 
contributed to the fatal issue, for two weeks later the patient died 
suddenly in collapse. Autopsy proved the diagnosis. The principal 
cyst, an old one, appeared to be attached to the apex of the heart 
and to bulge through the pericardium, displacing the left lung 
upward. A second, smaller cyst arose from the right ventricle. 
The fact that numbers of cases of hydatid cysts of the heart 
occur in subjects with no other involvement, suggests that the origi- 
nal embryo, after entering and passing the hepatic and pulmonary 
circulations, lodges in the heart wall. The development of the cyst 
is disturbed by the motion of the heart, and therefore early rupture 
is common. Metastatic cysts develop in the brain, lungs or else- 
where depending upon the site of rupture, and providing, of course, 
it is not in itself a fatal catastrophe. It is hardly possible that 
cysts are engrafted into the pericardial sac and heart from the 
lungs and mediastinum. These regions are usually proved to be 
secondarily involved. 
Lungs.—In this situation, while most often single, and in the 
right lower lobe, echinococcus cysts have been reported in both lungs 
simultaneously, in other lobes, and as multiple cysts, to say nothing 
of the complications. The two conditions under which the disease 
is found in the lungs are: (a) Entirely within the lung, arising 
•within the lung, and (6) as extensions into the lung from the 
mediastinum or from beneath the diaphragm, propagation from 
colonies in the liver, lesser omentum, etc. 
In the first instance, entrance is usually gained by way of the 
blood-stream—brood-capsules, primary embryos or scolices having Fig. 3. 
Author’s case of echinococcosis in an ape (Cynocephalus porcarius). The cysts shown occupy most 
of both lower pulmonary lobes. Collapsed cysts are shown exuding from the incisions through the 
parenchyma. Microscopically, the latter showed patches of broncho-pneumonia. The adventitia was 
very poorly defined, being practically the compressed lung tissue. The pathology is identical with that 
found in the human subject. 
Fig. 4. 
Left: Two cysts of spleen of an ape (Cynocephalus porcarius). The contents of the upper 
one have been partially evacuated in order to show the thickness of the cyst-wall. Collapsed 
daughter-cysts are shown exuding from the opening made in the cyst at the lower pole. Right: 
Two cysts adherent, as removed from the lesser omentum. The lower one has not yet been opened. Fig. 5. 
Portions of cyst-membrane and collapsed cysts from the Author’s case. The smallest mass is 
from the lung, and consists of a number of thicknesses of cyst-membrane matted together, and is of 
the consistency of the white of a very hard-boiled egg. Fig. 6. 
Liver of ape with echinococcosis, showing collapsed cyst exuding from a large cyst on the 
upper surface of the organ and one between the right and left lobes from which section has been 
taken. (Author’s case; Cynocevhalus porcarius.) Fig. 7. 
Liver showing one partly evacuated cyst on the superior surface, and one unopened cyst which 
was adherent to the inferior vena cava and the retroperitoneal structures. The upper cyst might 
have been approached through the pleura, but the lower cyst could never have been removed; 
surgically, nor could its presence have been determined in routine exploration of the abdomen. ECHINOCOCCUS DISEASE 
273 
entered a remote vein, or the afferent pulmonary circulation. That 
this type of infestation of the lung occasionally follows fracture of 
a hydatid-infested bone, adds confirmation to the work done by 
Fritsche, Caldwell and Huber,29 and others on fat embolism after 
fracture of long bones; in this instance, tiny cysts or scolices take 
the place of fat-embol. In a previous paragraph the improbability 
of air-borne infestation has been discussed. In the case of propa- 
gation of cyst-colonies from contiguous structures, what has been 
said for cysts extending into the lungs from the liver will suffice 
to illustrate the process. 
Small cysts cause little inconvenience. Large cysts or multiple 
cysts, however, cause compression of the lungs, give rise to hemor- 
rhage, and, on rupture, may cause death from suffocation: The mem- 
brane or cysts occluding the bronchi, or the fluid causing drowning. 
If, on the other hand, a fatal issue does not follow the rupture of 
a cyst, the fluid, membrane, daughter-cysts and scolices may be 
expectorated. The resulting cavity in the lung parenchyma usually 
becomes infected secondarily, and soon the picture of lung abscess 
is superimposed upon echinococcosis. 
In the case of the ape reported by the author, death was probably 
due to suffocation following rupture, for a fit of coughing preceded 
his demise, and at autopsy, detritus from the cyst in the lower left 
lobe was found in the communicating bronchi. The cyst of the 
right lower lobe was still intact, and contained many collapsed 
daughter-cysts, some of them undergoing calcareous infiltration. 
Both cysts were adherent to the diaphragm, and portions of that 
structure had to be removed with the lungs, so dense were the 
adhesions. It is entirely possible that this is an instance of the 
extension through the diaphragm by way of the veins of the round 
ligament, and radicals which anastomose with the phrenic veins. 
Microscopic sections of the lung from areas near the cysts showed 
patches of broncho-pneumonia, and it is of course possible that 
this condition, and not suffocation, as was originally thought, was 
the actual cause of death. It may be said here that it is very 
difficult, in sectioning specimens of lung tissue, to include the cyst, 
as the development of the ectocyst is very slight, and there 274 
INTERNATIONAL CLINICS 
is almost no attachment between it and the outer laminated layer 
of the true cyst. 
Cases have been reported of echinococcus cysts which have com- 
pressed the lung tissue as they enlarged, gradually displacing the 
heart and other mediastinal structures. Bulging of the chest-wall 
and displacement of abdominal organs is still a later stage of the 
process. Rupture may occur into the bronchi, pleura, pericardium, 
great vessels, or through the chest-wall. Often, in the case of 
rupture into the bronchi, no harm seems to result, even though the 
cyst be a huge one, and unless other cysts are present, complete 
recovery follows. However, Cordier30 recently studied five cases 
of pulmonary echinococcosis in which after rupture of the cysts 
and consequent injury to the parenchyma, either pneumococcic or 
tuberculous infection set in. He considers this form of infection 
rather unique. Authors have repeatedly stressed the clinical resem- 
blance between hydatid disease of the lungs and pulmonary tubercu- 
losis and broncho-pulmonary spirochetosis. 
Pancreas.—Echinococcus cysts of this organ are extremely rare. 
Masseron,31 a decade ago, was able to collect only five cases from 
the literature. Recently, Albo, of Montevideo, Uruguay,32 published 
an excellent article on hydatid cysts of the pancreas with a review 
of a number of cases from the literature. He quotes statistics of 
Ueisser to show that no case was found in 983 patients showing 
the disease elsewhere in the body. Also: “ Feichman, among 2452 
cases found only three, two of which were taken from the English 
literature and one from Russian ”... He could not find more 
than twenty-four cases in the literature of all periods, and states 
that probably some of these are not genuine. I am unable to find 
a case recorded which was diagnosed before autopsy or operation. 
Erom an experimental point of view, most authorities agree 
that the factor of safety is high, in that two-thirds of the pancreas 
can be removed in an otherwise normal individual. It is therefore 
safe to assume that replacement of two-thirds of the substance of 
the gland by echinococcus cysts, other things being equal, would 
not be fatal in itself. Graham, of Sydney, Australia, observed a 
hydatid cyst three inches in diameter which had replaced the head 
of the pancreas. Allen, Sweet, and others have shown that a rela- ECHINOCOCCUS DISEASE 
275 
tively small mass of normal island tissue can prevent the development 
of diabetes in dogs. Chutro (quoted by Albo) states that in the 
presence of hydatid cyst there are no microscopic signs of sclerosis 
or congestion of glandular tissue. No cases of rupture of the cyst 
into the digestive tract or elsewhere have been observed. Biliary 
and pancreatic obstruction have been reported in cysts occupying 
the head of the organ. As might be expected, the signs of the 
disease in the pancreas are not peculiar to this affection alone, but 
are those of any mass occupying this organ. An exceptional case 
is reported by Chaud 33 in the Indian Medical Gazette, of a child 
four years of age, whose pancreas (?) had been removed two years 
before with a large cyst of the organ, and whose urine has always 
remained free of sugar. 
Kidneys.—Many cases of echinococcus disease of the kidney 
have been reported. Cysts are almost invariably present in the 
liver at the same time. The left kidney seems to be more often 
affected than the right, although the involvement is at times bilateral. 
The cyst may grow in the perirenal connective tissue or beneath 
the true capsule. Many attain very large size, some extending 
upward have been reported as rupturing into the bronchi. Roberts 
(cited by Ransohoff, “Keene’s Surgery”) states that in a review 
of sixty-five cases, he found fifty-two cases of rupture into the renal 
pelvis. In the latter instances, fluid, vesicles and cyst-debris flowed 
down the ureter and were discharged per urethram. In these cases 
diagnosis is of course a fairly easy matter, and this is often a satis- 
factory but painful mode of termination. When the cysts are very 
small, they occasion no distress, and are found only at autopsy. 
When large, a pyelogram may give a clue because of distortion or 
depression of the calyces. 
Kretschmer34 quite recently reported the eighteenth case of 
renal hydatid occurring in the United States and Canada in the 
entire period prior to 1923. As is the case with most other organs, 
the infection in the kidney may be of two types: (a) Primary, in 
which thorough examination fails to reveal involvement of any 
other organ, and (b) as a part of a generalized echinococcosis. 
Although statistics of various authors differ, it may be said that 
the kidney is involved in about 1 per cent, of cases of the disease. 276 
INTERNATIONAL CLINICS 
Kretschmer’s case was of the primary type, and was in a young 
Greek. Ilis report is interesting and complete and valuable reading 
to anyone seeking information on renal hydatid. 
Where there are any symptoms, hematuria, the passage of cysts 
or debris, and a urine of low specific gravity are almost constant. 
Fullerton,35 in a study of “ unilateral diuresis,” reports an unusual 
ease of hydatid of the kidney in which the urine from the sound 
kidney was normal in character and small in amount, while that 
from the ureter of the affected side was “ watery, opalescent, neutral 
in reaction, had a specific gravity of 1005, and contained a trace 
of albumin, a few leucocytes, ureteral epithelium, an occasional red 
cell, but no booklets.” 
Ductless Glands.—The disease is rarely met with in these 
organs. When affected, the mode is either by direct hematogenous 
implantation of embryo or brood-capsule, or by extension from a 
colony in a neighboring tissue. 
Mammary Gland.—A number of cases of echinococcus disease 
of this gland have been recorded in the literature. For a time there 
was much confusion owing to an error on the part of Sir Astley 
Cooper, who, in 1837, referred to cystic disease of the breast as 
“ hydatid disease.” Instances are on record of the existence of 
colonies of cysts in the breast for periods as long as ten years, the 
parasites causing no inconvenience. A cyst in this gland may 
attain the size of a child’s head (Bland-Sutton). Finney states that 
in the young, the disease is usually diagnosed as a benign tumor, 
while in the aged, the pre-operative diagnosis is usually given as 
carcinoma. Le Conte, in 1901, reported a single case and was 
unable to find another in American literature. 
Uterus and Adnexa.—In this situation echinococcus cysts are 
usually observed growing beneath the peritoneum, and usually as 
a part of a general invasion of the subperitoneal tissues. Growing 
beneath the peritoneal investment of the uterus, the cysts are usually 
pedunculated, and resemble subserous fibroids. The most common 
point of infection is the pelvic cellular tissue between the folds of 
the broad ligament. In this situation, as they enlarge they are 
prone to involve the uterus, fallopian tubes, bladder and rectum. 
They frequently simulate in growth and gross appearance ovarian ECHINOCOCCUS DISEASE 
277 
and parovarian cysts. Where the ovary is involved, there is prob- 
ably always an involvement of the cellular tissue first. Maloney 
reported a remarkable case of a colony 11 centimetres in diameter 
growing beneath the serosa of the uterus and communicating with 
the right fallopian tube, which was greatly distended, thrown into 
convolutions, and stuffed with vesicles. 
Brain.—Hydatid cysts occur in this organ occasionally, entering 
it from the meninges or from the blood-stream. Most intracranial 
echinococcus cysts originate in connection with the pia mater, where 
they develop without much opposition, and therefore frequently lack 
the fibrous adventitious cyst so commonly present in the more solid 
organs. Furthermore, these cysts are usually sterile, a fact which 
is possibly responsible for some erroneous diagnoses. The fact that 
Cysticercus celluloses, Cysticercus tenuicollis, and the larvae of 
Tcenia pisiformis, Taenia ovis, and Multiceps multiceps have been 
reported for the brain, makes it still more confusing. 
One of the most interesting cases on record is that of Cardenal 
and Castella,36 who operated on a boy of fourteen one year after a 
fall on the right parietal region which had caused unconsciousness 
for two hours. In the interval between accident and operation, the 
child had epileptiform seizures with coma, which lasted two or 
three minutes, and which recurred every six or seven days, finally. 
A right partial hemiplegia also manifested itself. The skull was 
opened widely in the left rolandic region. The dura beneath the 
fiap was intact. On incising this structure, however, there was an 
outpouring of echinococcus daughter-cysts. The mother-cyst occupied 
the space of the anterior third of the left hemisphere, and extended 
beyond the median line internally. In view of the large area of 
brain involved, the symptoms were remarkably mild. The child 
made a good recovery with the exception of a slight flaccid palsy 
and lack of power to extend the fingers of the right hand. At the 
seventh month post-operative he had an epileptic seizure, but up 
to the tenth month, there had been no recurrence. 
Morquio, of Argentina, has had seven cases of hydatid of the 
brain in children. There was no eosinophilia in any of the cases, 
lie states that 5 per cent, of brain tumors, in a series he has observed 
in children, were echinococcus cysts. They may attain great size 278 
INTERNATIONAL CLINICS 
and cause protrusion and thinning of the skull before there is head- 
ache, vomiting, or eye symptoms. Sometimes the mind is affected, 
sometimes there is a unilateral chorea, and sometimes there is sudden 
death with the cause only apparent at autopsy. Rupture of a cyst 
in the brain will almost certainly prove fatal, anaphylactic shock, 
urticaria, cyanosis and collapse preceding death. 
Cranium and Spine (Axial Skeleton).—Several cases of echino- 
coccus cysts between the tables of the skull have been reported, 
and Verco, Rennie and Crago, Mills and MacCormick, and others 
have reported cysts within the cranium which were extracted after 
exposure with the trephine. A number of cases have been observed 
of colonies of cysts within the orbit. 
Cysts occur in connection with the spine under the following 
conditions (Bland-Sutton) : 
I. Cysts situated entirely within the canal: (a) Between the 
dura mater and bone, lying in the loose connective tissue ; (6) those 
inside the dura mater. 
II. Cysts arising in the vertebras and extending into the neural 
canal. Here the primary colony in the vertebra is usually of the 
multilocular variety. 
III. Cysts growing in the tissue adjacent to the spine may 
involve the vertebrae and extend into the spinal canal. 
Schlesenger tabulated 400 tumors of the spinal canal, and of 
this number, 44 were echinococcus cysts. Of the 44, five were found 
intradural, and 39 were extradural. His statistics again confirm 
the fact that echinococcus cysts choose loose cellular tissue, in 
this case the tissue external to the dura. Theobalds, in the Lancet 
of April 10, 1909, reported an interesting case of involvement of the 
fourth and fifth lumbar vertebrae. 
Other Bones (Appendicular Skeleton).—Comparatively few 
cases are on record of echinococcus invasion of the bone. Walker 
and Cummins 37 being able to find records of only 88 cases in the 
literature up to 1917. They quote Alexinskv’s statistics which show 
improvement in 1.9 per cent, of 1950 cases of the disease. This 
figure corresponds closely with the data of Gangolphe, who found 
bone involvement in 1.7 per cent, of 3000 cases of the disease in 
the literature. The multilocular variety of the cyst is practically ECHINOCOCCUS DISEASE 
279 
always present, and the medullary cavity is occupied by a multitude 
of vesicles not contained in a mother-cyst. Pressure from within 
results in atrophy of the shaft of the bone, and fracture is apt to 
result from trivial violence. Eisendrath was able to collect eighteen 
cases from the literature, of pathologic fracture due to echinococcus 
cysts. The colonies may occur in the cancellous tissue at the ends 
of long bones as well as in the medullary canal. From the cancel- 
lous tissue the process occasionally extends to the epiphyseal portion, 
and from there may enter the joint. 
The question as to the part trauma plays as a predisposing cause 
of bone hydatids is still under investigation. Walker and Cummins 
assign to it an important role. At operation or autopsy, an inflamma- 
tory periosteal thickening with atrophy of the bone is found. If 
the medullary canal has been invaded, its cavity is enlarged at the 
expense of the shaft. The X-ray is an aid in disclosing a rarefaction 
of the bone about a colony of cysts. Corlette 10 considers the con- 
dition quite analogous to sarcoma of bone as far as its tendencies 
to metastasize and to infiltrate are concerned. Indeed, clinically it 
must often be very difficult to differentiate between sarcoma, osteitis 
fibrosa cystica, and echinococcus cysts of bone, in that the latter are 
practically always very small, and are sterile. As in other organs 
and tissues, secondary infection is occasionally superimposed, and 
the condition changes to one of osteomyelitis. 
The femur is more frequently involved than any other bone in 
the body for the obvious reason that it is the largest. The other 
bones are involved to a great extent according to relative size. The 
analogy between fat-embolism and embolization with echinococcus 
brood-cysts has already been referred to. It is possible that bones 
are involved by direct hematogenous implantation of embryos which 
have filtered through the portal and pulmonary circulations. Statis- 
tics would seem to bear this out, in that visceral and osseous 
involvement seldom exist together in the same host. On the other 
hand, where visceral and osseous involvement do co-exist, it is very 
difficult to say which was primary. Lack of complete autopsies in 
proven cases of visceral involvement is another possible source of 
error, in that examination of the bones is seldom a part of such 
post-mortem examinations. It is safe to say that large numbers 280 
INTERNATIONAL CLINICS 
of instances of bone hydatids go unrecognized because of lack of 
symptoms and signs pointing to bone involvement. 
Muscles, Subcutaneous Tissues and Cellular Tissues.—Colonies 
of echinococcus cysts may arise in the subcutaneous tissue in any 
part of the body. In the neck the colonies seem to prefer the 
subfascial spaces, where they are rather difficult to deal with sur- 
gically. Haderern (quoted by Andrews) reported a deeply sit- 
uated cyst which was attached to the internal carotid artery. This 
vessel had to be ligated in order to completely remove the cyst. 
The patient recovered. Andrews was able to collect twenty-nine cases 
of involvement of the tissues of the neck, in the literature up to 1907. 
Of this number, the majority were instances of infestation of the 
thyroid gland, while the next most frequent site was beneath the 
sternomastoid muscle, and extending deeply to the carotid sheath 
or beyond. In this latter position hydatids are frequently mistaken 
for branchial cysts, while in the former location, they are apt to 
be confused with cystic goitre. Because of the firmness of the fascia 
of the neck, cysts tend to become loculated as they thrust themselves 
into the free spaces. 
In the abdominal and thoracic walls, the parasite usually chooses 
the muscles, and next in frequency the properitoneal and subserous 
tissues of the abdomen and chest, respectively, are involved. In 
the abdominal wall, the cysts are usually reported in the neighbor- 
hood of the umbilicus, although Madelung found them mostly in 
the lumbar region. In the vast majority of cases, intra-abdominal 
cysts are also present, and no doubt these are the primary foci in 
many cases. The mode of probable communication is between the 
portal and systemic circulations. 
Statistics show that the muscles are invaded in about 1.9 per cent, 
of cases. The embryo or brood-capsule is brought to the muscle by 
the blood-stream, and once deposited, it undergoes the usual trans- 
formation. The resulting cyst pushes the muscle fibres apart in 
its growth, until it attains its full development, usually about five 
centimetres. The perimysium forms the outer fibrous or adven- 
titious capsule, and because of the chronic irritation of the foreign 
body, there is usually more or less inflammatory reaction on the 
part of the adjacent tissues. If secondary infection takes place, ECHINOCOCCUS DISEASE 
281 
abscess results, while if in the course of time, the cyst contents die, 
caseation results or calcium salts are deposited in the mass. Munro 
recorded a case of echinococcus cyst in the retroperitoneal tissues of 
the flank which had caused pressure atrophy of the kidneys. At 
operation, cyst and kidney were both removed. 
When infections are present a leucocytosis with eosinopliilia may 
be found, but in chronic cases no general systemic reaction is mani- 
fested. The cysts may or may not be sterile. They are occasionally 
mistaken for Cysticercus celluloses. 
Peritoneal Cavity.—Involvement of the peritoneal cavity is 
usually secondary to cysts of the contained organs such as the liver 
and spleen. These cysts may have ruptured spontaneously or been 
ruptured at operation and have sown the brood-capsules and daughter- 
cysts upon the serosa, or by exogenous budding from the mother-cyst, 
propagation of colonies on the peritoneum may have taken place. 
The appearance of the serosa resembles a tuberculous infection 
grossly, and is also to be differentiated from infection by the cysti- 
cercus tenuicollis. 
Fairley38 recently analyzed twenty-five cases of peritoneal 
echinococcosis and found that 88.2 per cent, of the cases had been 
operated on previously for intra-abdominal hydatid. In seventeen of 
the twenty-five there were multiple cysts. In five of the cases, calci- 
fication or other degenerative change had taken place. He holds the 
belief, in common with several other observers, that single cysts argue 
for a primary localization of an embryo after traversing the wall of 
the gut, or arriving via the blood-stream from some distant focus. 
With leakage of these cysts there is the usual anaphylactic reac- 
tion. With secondary infection there develop the localizing signs 
of abscess, and the typical systemic reactions. Pelvic cysts produce 
pressure symptoms earlier than do those situated higher up. 
Prostate Gland.—Young, of Baltimore, states that echinococcus 
cysts of this organ have been described by Nicaise, Lodwell, 
Winterberg, Butreuille, Tillaux and Millet, and others. It is prob- 
able that the great majority of cysts which involve the gland arise 
in the pelvic cellular tissue primarily. Thus, Bird 39 reports three 
cases of pelvic hydatids, in all of which the prostate became seconda- 
rily involved, and daughter-cysts and debris were passed per urethram. 282 
INTERNATIONAL CLINICS 
SYMPTOMS AND PHYSICAL SIGNS 
Occurring as they do in a multitude of locations, the cysts are 
bound to produce a multitude of different symptoms, and few symp- 
toms, if any, which are pathognomonic of the disease itself. The 
size and situation of cysts with reference to vital structures has a 
great deal to do with the chain of symptoms presented. 
To begin with the head, if the colony is extradural, or between 
the tables of the skull, no symptoms are present as a rule unless on 
increase in size, there is pressure on the brain or irritation of the 
scalp over the prominence. Within the brain, pressure on various 
centres will produce symptoms pointing to the area involved. If in 
the motor area, Jacksonian epilepsy is quite common as in the case 
already referred to of Castella and Cardenal,36 in which there 
was a cyst of the anterior third of the left hemisphere. There was 
a partial right hemiplegia in addition to the epilepsy. Headache 
is the commonest symptom. Objectively, “ egg-shell crackle ” of a 
thinned cranium may lead to a diagnosis if other signs agree, and 
the biologic tests are positive. 
In the neck, the chief symptoms are those of discomfort due to 
the swelling, and if close to the trachea, there is apt to be dyspnoea, 
while pressure on the sympathetic may produce pupillary changes; 
in short the symptoms are very variable, and depend on the pressure 
exerted on certain structures by the growing cyst. The cysts are 
said to be hard, and do not fluctuate as a rule. The “ hydatid thrill ” 
is demonstrable in perhaps half the cases. Pain is not present as 
a rule unless secondary infection takes place, when there is added to 
the picture the phenomena of sepsis. A severe urticaria follows 
dribbling of the fluid into the subcutaneous tissues after explo- 
ratory puncture. 
In the chest, symptoms and signs are not usually manifested 
unless the heart, lungs, or great vessels are involved. When there 
is an involvement of the heart itself, it may readily be seen at 
what mechanical disadvantage the heart has to work. Pressure on 
the neuromuscular conduction fibres would have the effect of inter- 
fering with impulses to ventricular contraction. Then too, the 
accidents of rupture and secondary infection carry with them ECHINOCOCCUS DISEASE 
283 
a separate and grave set of symptoms depending largely on the 
position and size of the cyst. Either accident is usually fatal. 
Large cysts in the lungs present the symptoms and signs of 
intrathoracic tumors, and pressure signs sooner or later become 
rather prominent. Dyspnoea on exertion and the development of 
an afebrile cough, with occasional hemoptyses might lead to a diag- 
nosis. There is sometimes a profuse foetid expectoration, emaci- 
ation and all signs of pulmonary tuberculosis. Where the cyst or 
cysts rupture into the bronchial tree without fatal effect, a diagnosis 
is easily made by the finding of the cyst-elements and a large amount 
of clear fluid. A common sequel of such rupture seems to be secondary 
infection with resulting lung abscess, and the clinical phenomena 
of sepsis. Signs of tumor of the lower lobe of the lung, which tumor 
gradually enlarges and displaces thoracic and abdominal viscera 
without an accompanying clinical picture of malignancy or sepsis, 
should put one on his guard for echinococcus disease. (See “Diag- 
nosis,” p. 284.) A round shadow is shown by the X-ray. 
In the abdomen, a painless swelling connected with the liver 
or spleen, and which gives a vibratory thrill on percussion, should 
be suspected of being an echinococcus cyst, especially if the history 
is suggestive, and there is no evidence of malignancy or syphilis. 
When these cysts rupture into one of the hollow viscera, and their 
contents are discharged, the diagnosis is a simple matter as a rule. 
When secondary infection takes place, the picture changes to that 
of sepsis. 
In the case of the long bones, the symptoms are those of a slow, pro- 
gressive increase in the size of the bone. In the later stages, pain 
is complained of, and is worse at night. There may be some cedema 
of the overlying structures, but no inflammatory reaction is present. 
“ Egg-shell crackle” is eventually elicited, and when this point is 
reached, spontaneous fracture is a common accident. Secondary 
infection results in osteomyelitis with the symptoms and signs that 
accompany that affection. In Walker and Cummins’ case,37 the 
Greek, thirty-one years of age, had complained of paroxysmal pain in 
the upper third of the tibia for about three years. The pain was 
worse at night. iVt times the leg became much swollen over the 
area of pain. There was no history of syphilis, trauma, or association 284 
INTERNATIONAL CLINICS 
with dogs. He was poorly nourished, but presented no evidence of 
tuberculosis. Blood and urine were negative. X-ray examination 
showed a cystic condition of the upper third of the tibia. The defi- 
nite diagnosis was made at operation. 
A complete description of the adult parasite is given in a pre- 
vious paragraph. As the principal pathology, and the phenomena 
which affect man are limited to the larval cycle, the cyst stage, it is 
this aspect only of the disease which will here be considered. The 
diagnosis is made by a process of exclusion in the majority of cases, 
if indeed a diagnosis is made at all before operation or autopsy. 
In countries where the disease is rare, the diagnosis is seldom made 
until the cysts are discovered in the course of operation or autopsy. 
And yet there are very definite reasons why a diagnosis should, if 
possible, be made before any surgical treatment is instituted. 
Volkmann (1887) early called attention to the dangers from punc- 
ture of these cysts. The immediate danger is from anaphylactic shock 
due to spilling of cyst-fluid, and the remote danger is from the 
implantation of elements which may develop into new cysts. 
In countries where the disease is prevalent, very commonly the 
diagnosis is arrived at through the medium of the complement- 
fixation test, the precipitin reaction, or one of the other biologic tests. 
The complement-fixation test (first used in the diagnosis of echino- 
coccus disease by Apphatie and Lorentz, in 1908, in Argentina 16) 
is applied in the same way as is the Wassermann reaction. Ehrlich 
showed that hydatid disease produces in the host antibodies of the 
third order. In this instance, the preserved fluid from a human 
or animal hydatid cyst is used as antigen. 
The materials required for the test are: (a) Antigen, fluid from 
a known echinococcus cyst; (&) complement, normal guinea-pig 
serum; (c) serum of the patient suspected of having the disease, 
the serum having first been inactivated by heating to 54° C. for 30 
minutes (to destroy complement); (d) sheep amboceptors; (e) a 
2.5 per cent, mixture of defibrinated sheep erythrocytes, free from 
serum and suspended in normal saline. 
The precipitin reaction (Fleig and Lisbonne, 1907) is conducted 
DIAGNOSIS ECHINOCOCCUS DISEASE 
285 
as follows: Equal parts of the patient’s serum and hydatid fluid 
(obtained under aseptic precautions from another patient or one 
of the animal hosts) are mixed. A distinct flocculent precipitate in 
5 to 30 minutes indicates a positive reaction. If after one hour the 
mixture is clear or only slightly turbid, the test may be regarded as 
negative. Simultaneous controls should be run, using serum of 
normal person and that of a patient known to have the disease. 
Casoni’s method of intradermal injection is by far the simplest 
test, and according to Pontano 40 is positive in 84 per cent, of cases. 
By this method 0.2 to 0.3 c.c. of fluid from a hydatid cyst of an 
animal is injected into the skin of the patient. If positive, a local 
reddening and an urticarial wheal develop. In his experiments, 
Pontano found that subcutaneous injection produced a reaction in 
66 per cent, of cases, the complement-fixation test was positive in 
only 50 per cent., and an eosinophilia was present in only 40 per 
cent, of cases. He is enthusiastic over the intradermal test because 
of its high percentage of positive results, and because the complement- 
fixation test is negative when suppuration is present in the cyst, 
while the Casoni test is often positive even with this complication. 
He found suppuration in the cyst to be the principal cause for the 
negative reactions sometimes obtained. He states that fluid from 
a hydatid cyst is an antigen capable of sensitizing normal persons. 
On the other hand, such investigators as Zapelloni,41 in a series of 
500 collected cases, found the complement-fixation test positive in 
93 per cent., whereas Luridiana 42 investigated both the complement- 
fixation and the intradermal tests in his series of cases, and found 
one was sometimes positive when the other was negative. He 
therefore advises using both tests on each suspect. Everything 
considered, it would seem that Luridiana’s advice is worth following 
where possible. 
There are three other tests deserving of mention. These are: 
(1) The miostagmin reaction of Ascoli (1910) which consists ir 
mixing nine parts of the patient’s serum with one part of antigen? 
and counting the number of drops, in a unit of time, which flow 
from a Traube stalagmometer; (2) the Abderhalden test which com 
sists of the dialization and extraction of an emulsion of equal parts 
of antigen and the patient’s serum; (3) the cutaneous test, done with 286 
INTERNATIONAL CLINICS 
sterile hydatid fluid much as one would do the Von Pirquet test, 
the principle being to show a specific allergic reaction as in similar 
tests for protein sensitization. 
Blood examination in an uncomplicated case of hydatid disease 
may reveal a small percentage of eosinophiles. After puncture of 
a cyst, or rupture, there is apt to be a definite eosinophilia. How- 
ever, many authorities place no confidence in eosinophilia as deter- 
mining the presence of the disease. 
The X-ray is regarded by some as being very valuable in the 
diagnosis of the condition in the lungs. This is probably true when 
confirmed by history, symptoms, physical signs and biologic tests. 
The X-ray shadow is round with well-defined borders, in contrast 
with cancer, abscess (?) and tuberculosis, in which conditions the 
shape is usually irregular, and the borders ill defined. The fluoro- 
scope will differentiate the pulsations of an aneurism from the non- 
pulsating cyst. The X-ray in other parts of the body is of much 
less value in diagnosis. The cyst-mass shows as a dark shadow as 
a rule. In the case of the liver, if the cysts be of the upper portion 
organ, the diaphragm is elevated, in contradistinction to a hydro- 
thorax, where the dome of the diaphragm is depressed. 
Exploratory puncture is to be condemned except in the most 
superficial cysts, e.g., those under the skin, or in easily accessible 
muscles, where excision or marsupialization can be carried out if 
a cyst is proven to exist. Here, the finding of a clear, neutral, non- 
albuminous fluid of 1.005 to 1.015 specific gravity, and containing 
hooklets or scolices, is fair presumptive evidence of the disease, 
cysticercus cellulosse having been carefully ruled out. The fluid is 
said not to he toxic to laboratory animals, whereas the fluid from 
cysticercus tenuicollis, cysticercus cellulosse and other cestode larvae 
is more or less toxic, producing urticaria and other allergic symp- 
toms on injection. The specific toxin is said to be a leucomain or 
a body close to histamine. On the other hand, if any of the fluid 
is spilled into the tissues during withdrawal of the needle, or during 
operation on a cyst, an urticaria is sure to result, in the human 
subject, and if much fluid is spilled, violent intoxication, and even 
death, may result from anaphylactic shock. 
The life cycle of the parasite has been discussed, and under that ECIIIXOCOCCUS DISEASE 
287 
heading the chief characteristics of a cyst were mentioned. How- 
ever, owing to the necessity for making a definite diagnosis before 
operative drainage or removal is undertaken, the chief points which 
distinguish the echinococcus cyst will be delineated: In the first 
place a cyst or cysts sufficiently large to produce symptoms or to be 
palpable through the abdominal wall, or to throw a characteristic 
shadow upon an X-ray plate, will usually be found at operation 
to be not less than four to six centimetres in diameter. Echinococcus 
cysts have been reported as large as a child’s head. In the solid 
organs of the abdomen, they are usually found presenting one-fourth 
or more of their surface into the peritoneal cavity. The remainder 
of the cyst is embedded and, if near the edge of the organ, may be 
palpable almost in its entirety. Cysts in the omentum may be 
brought out of the wound and examined carefully. 
Beneath the smooth peritoneal covering will be seen the fibres 
of the laminated adventitious coat which is supplied by the invaded 
organ. If this is incised or bluntly separated over the convexity of 
the cyst, the glistening, pearly white, outer coat of the cyst- 
parenchyma is exposed. If now, with proper precautions this layer 
is excised through its entire thickness, fluid and small cysts and cyst- 
membrane will exude from the opening. If the fluid is examined 
under the microscope, it will be found in a fair proportion of cases 
to contain scolices and hooklets. This is the most characteristic 
feature of the cyst produced by the embryo of Taenia, echinococcus, 
that it produces thousands or even millions of scolices which spring 
from a single onchosphere. The larvte of other taenia produce one 
or at most only a few scolices. 
As already stated the cyst-wall is chemically allied to chitin, or 
is between it and the proteins. When boiled with acid, this yields 
50 per cent, of a reducing sugar-like body. Glycogen is usually 
capable of being demonstrated but is limited to the germinal mem- 
brane (Wells). 
As has been said, the contained fluid is of a specific gravity 
between 1.005 and 1.015. It contains about 1.5 per cent, to 2 per 
cent, of solids, 0.8 per cent, of which is sodium chloride and 0.25 
per cent, sugar. The molecular concentration of the fluid is about 
the same as the patient’s blood (Schilling; Wells). Proteins are 288 
INTERNATIONAL CLINICS 
present only in traces except where inflammation exists. Cholesterol 
is often abundant, while inosite, creatin and succinic acid are fre- 
quently present in traces. 
The following cystic conditions are to be considered before diag- 
nosing echinococcus disease in the absence of scolices and hooklets: 
Retention, distention and exudation cysts; proliferation cysts; con- 
genital cystic disease (as of the liver, kidneys, and rarely of the 
pancreas); hemorrhagic cysts; pseudocysts, as of the pancreas, not 
arising in the substance of the gland itself; ovarian and parovarian 
cysts; and last, but not least, in importance, Cysticercus tenuicollis 
(the larval stage of Tcenia hydatigena), which has frequently been 
reported for man. In the abdomen it (Cysticercus tenuicollis) is 
found embedded in the liver, or, more often, hanging from its surface 
or attached to the mesenteries or omenta. It resembles a sac full 
of clear fluid, with a white object (the head and neck) projecting 
into it from one end. It is ovoglobular, about 2.5 centimetres in 
diameter, and perhaps five to seven centimetres in length. As in 
the case of the echinococcus cyst, the host throws about the cyst an 
adventitious coat as protection. If this coat is broken through, and 
the parasite shelled out, it is found to be a thin-walled bladder, from 
one end of which the single scolex may be expressed. 
In bone, the chief conditions to be excluded are sarcoma, oste- 
omyelitis, and osteitis fibrosa cystica. In the chest, neoplasm, 
aneurism, tuberculosis, broncho-pulmonary spirochetosis, and pneu- 
monia are to be excluded. Fagiuola, in 1919, reported a case of 
“ primary echinococcus of the lung ” which was diagnosed by the 
X-ray, and confirmed by puncture and complement fixation. The 
original diagnosis was broncho-pneumonia with infiltration of the 
upper and middle lobes of the right lung, plus pleurisy with effusion 
on the same side. X-ray showed three large cysts, two in the lung, 
and a third in the posterior pleural sac. The puncture—a procedure 
which is not recommended—was followed by the usual symptoms of 
anaphylaxis, and by the appearance in the sputum of a large number 
of eosinophilia. 
Cysts in the subcutaneous tissues are to be differentiated from 
wens, dermoids and lipomas. ECIIIHOCOCCUS DISEASE 
289 
The differential diagnosis in the abdomen involves the follow- 
ing considerations: 
(a) A gumma of the liver is firm, painless and rarely fluctuates. 
There are other evidences of syphilis; (&) a cancer of the liver is 
to be excluded by the history of the case and the absence of a primary 
growth, as well as by the biologic tests. Primary carcinoma is rare, 
and usually requires laparotomy for diagnosis; (c) hydronephrosis 
and congenital cystic disease of the kidney are to be excluded by 
history, symptoms, ureteral catheterization, pyelography, etc.; (d) 
abscess of the liver is ruled out by the local signs of suppuration and 
the general symptoms of sepsis in this condition; (e) subphrenic 
abscess is to be excluded. Here as in right-sided empyema, the symp- 
toms of sepsis would preclude the presence of uncomplicated echino- 
coccus disease. 
In short, a slow-growing, painless, swelling or fluctuating tumor 
connected with the liver or presenting in the epigastrium, should be 
suspected as an echinococcus cyst, and especially in the presence 
of hydatid fremitus, positive biologic tests, and an eosinophilia. 
PROPHYLAXIS 
In prevention lies the best remedy for this scourge, and, as has 
been shown, it is a scourge in some countries. It is already a menace 
to the health of many communities in Horth and South America 
to-day. I cannot do better in this connection than to mention the 
work of Maurice C. Hall, and to quote from the outline contained 
in a concise little booklet by him, “ Farmers’ Bulletin 1150 ” 
(United States Department of Agriculture, Bureau of Animal 
Industry, 1920). What he says regarding sheep holds true, in many 
particulars, with reference to hogs, other domestic animals, and 
even man: 
“ Sheep probably suffer more from parasites than do any other kind of 
livestock. Most of our loss in sheep, mutton, and wool is from animal parasites, 
as sheep suffer comparatively little from bacterial diseases. Lambs and young 
animals are most susceptible to parasites and suffer most from them. It is the 
sheepman’s business to prevent disease. When disease is present it is desirable 
to call in a competent veterinarian. Pasture rotation, use of forage crops, feeding 
from racks or bare floors, draining or filling swamps, and restraint of wandering 
dogs {ire measures of value in parasite control. Permanent pastures perpetuate 
parasites! Parasite eggs pass in the manure usually. The disposal of the manure 290 
INTERNATIONAL, CLINICS 
determines the fate of these eggs. Parasitized animals usually do not have fever; 
they are unthrifty. This unthriftiness may have a fatal termination. Act 
promptly to ascertain the trouble when sheep become unthrifty. A post-mortem 
examination of one of the sick animals may disclose the trouble and save 
the others.” 
In still another bulletin, Hall calls attention to the recent abattoir 
figures which show an alarming increase in the incidence of the 
disease in domestic animals in some parts of the United States, 
especially in Virginia, Arkansas, and Oklahoma. Where the disease 
prevails among domestic animals, man is a potential victim, and it 
behooves the stockman, the veterinarian and the meat-inspector to 
be ever on the alert to interrupt the cycle in its incipiency. Finding 
of the disease in a drove of sheep or in a herd of cattle or swine 
should be equivalent to signing a life-time quarantine for faithful 
Rover. He it is that harbors the adult worm, millions of them, 
probably, on the villse of his duodenum and upper jejunum. The 
Taenia echinococcus and the Tcenia nana are the smallest of all of 
the cestodes. Hall is quoted by Johnston and Willis (loc. cit.) as 
saying that “ the bare fact that hydatids occur at all in the United 
States is of itself a cogent argument for the suppression of the dog 
nuisance as a measure necessary for the public welfare.’’ 
Johnston and Willis 13 trace the small epidemic of the disease 
among human beings, which they report, to an epidemic among hogs. 
Indeed they liken the role of the hog in Virginia to that of the sheep 
in Iceland and Australia. It is often difficult to determine the exact 
mode of infection of man, whether through the ingestion of ova, 
or through the eating of infested organs of sheep or hog. We do 
know, however, that the dog is the primary host for the Tcenia echino- 
coccus in the vast majority of cases, and in Hall’s recommendations 
for the “ suppression of the dog nuisance ” seems to lie the solution 
of the problem where the disease is endemic. 
In the prevention of echinococcus infection, we are automatically 
preventing cysticercosis. Thus, Cysiicercus tenuicollis, which is 
reported as a comparatively frequent invader of the human body, 
grows from the eggs of Tcenia hydatigena, which worm resides in the 
small bowel of the dogs also. Careful autopsy of animals dying 
of any obscure infection is one of our best methods of gaining ECHINOCOCCUS DISEASE 
291 
knowledge which may save from infection other animals and man. 
I have called attention to the growing tendency to study the relation- 
ship of animal infection and infestation to human disease. Every 
city of any considerable size should foster a society of comparative 
pathology, so that outbreaks of epidemic disease in the lower animals 
may be discovered early, discussed intelligently by physicians, 
veterinarians and others trained in the medical sciences, and eradi- 
cated. Eot only epidemic diseases, but all diseases and anomalies 
should be aired in open forum in such a society or league, thus 
assuring better cooperation between the welfare organizations of 
the community. 
In this connection it will be of interest to quote from a resolution 
adopted in July, 1922, by the Society of Comparative Pathology 
of Paris, and presented by Doctors Deve, Weinberg and Morel 
(Paris letter to Jour. Am. Med. Asso., Aug. 4, 1922): 
“ Resolved : That private slaughter-houses be suppressed and be replaced 
by communal abattoirs. 
“ That the legislative enactments concerning the seizure of stray dogs and 
the destruction of animal carcasses be strictly enforced. 
“ That dogs should not be permitted to enter the flaying rooms at all, and 
the abattoirs only to a limited extent, as controlled by definite regulations. 
“ That the declaration of all animals discovered in the abattoirs to be infested 
with echinococci shall be obligatory.” 
It has been further suggested, that, in the regions where animals 
are discovered harboring the disease, the public, the farmers and the 
butchers be advised by articles in the daily papers, by leaflets, and 
by lectures, of the dangers of the disease and means to avoid it. 
It would seem to be desirable to mention first the treatment of 
the intestinal tseniasis in the primary host. Authorities seem to 
agree that dogs and cats should be kept free of tape-worms by giving 
them vermifuges every three or four months. In this way, too, 
by saving and examining the stool, one is able to determine which 
worm, if any, is present in the animal’s alimentary tract. Among 
the Taenia to be expected are T. echinococcus, T. hydatigena, Midti- 
ceps multiceps, T. nana, and T. ovis. The animal is fasted for 
eighteen to twenty-four hours, and is then given one to four c.c. of 
the oleoresin of male-fern in capsules. This dose is immediately 
TREATMENT 292 
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followed by an ounce of castor oil. Areca nut, if freshly ground, 
is preferred by some, while others administer kamala, two to six 
grams. In the case of the two latter remedies, if no bowel movement 
occurs in four or five hours, a purgative should be given. After 
examination, the faeces should be burned. Dogs persistently harbor- 
ing the tcenia should be exterminated. 
The only proper treatment of echinococcus disease in the second- 
ary host is surgery. The method of procedure will necessarily vary 
with the situation of the cyst itself. Aspiratory puncture is applic- 
able to only a very few cases, and is mentioned for the purpose 
of condemning it. The dangers attending the spilling of cyst-fluid 
during operation or puncture have been enumerated, and any plan 
of operation, to bring permanent cure must have as a fundamental 
principle, the safeguarding of exposed tissues. There is no excuse 
for such meddlesome methods as electrolysis. In general terms, the 
ideal of surgery is to remove the cyst in toto where possible, and if 
not possible, to remove as much as is practicable, and then either 
marsupialize or thoroughly drain. Aspiration remains as a last choice 
in those cases where none of the above procedures is applicable. In 
the treatment of echinococcus cysts of the liver, the technic of the 
Mayos will be found to embody the principles just mentioned. The 
operation of incision and enucleation of the cyst was first described 
in 1883 by Thornton. In France the same operation bears the name 
of Delbet. 
The steps of the operation are as follows: 
(1) The abdomen is opened by a vertical incision over the most 
prominent portion of the tumor, the incision extending a safe 
distance above and below the mass. 
(2) The cut edges of the parietes and the general peritoneal 
cavity are well protected by gauze packing to prevent implantation 
of cysts or scolices. 
(3) An aspiration trocar with rubber tubing connected is intro- 
duced into the cyst at a point where it comes nearest to the surface 
of the liver. As much of the fluid as possible is evacuated. 
(4) The trocar is withdrawn and the incision enlarged, extend- 
ing as far into the liver as is compatible with safety. 293 
ECHINOCOCCUS DISEASE 
(5) The edges of the wound in the liver are covered with gauze, 
and retracted. Bleeding is in this manner controlled. 
(6) The cyst is now opened and the contents are evacuated. 
(7) The mother-cyst is next removed. 
(8) Where possible, the cavity in the liver is closed with fine 
catgut on a curved needle—the procedure known as capitonnage. 
Where such closure is not possible, a few strips of rubber tissue are 
inserted and brought out through a separate stab-wound below the 
right costal margin. 
The operation of incision and drainage is the one usually per- 
formed. The steps are much the same as in the operation just 
described, except that the incisions need not be so large, either in 
the parietes or in the liver. After the cyst has been evacuated, its 
edges are carefully sutured to the parietal peritoneum, the process 
being known as marsupialization (Lindemann’s operation). If the 
cyst is small, a rubber drainage tube is inserted. If large, the cavity 
is packed with gauze plus a rubber drainage tube. An external 
dressing of dry sterile gauze is applied. The cavity is repacked at 
intervals until it contracts and is obliterated, the cyst-membrane 
usually being cast off in two or three weeks. In large cysts, healing 
sometimes takes six months, and then the defect must be closed by 
a plastic operation. In smaller cysts, the operation of “ capitonnage ” 
or obliteration of the cyst-cavity is often practised—using “ U ” 
sutures of catgut to approximate the walls. 
In the case of suppuration of an echinococcus cyst of the liver, 
either of the operations described may be performed, but ample 
drainage should be provided for. 
Cysts which protrude upward against the diaphragm from the 
right lobe may require the resection of a portion of two or three ribs 
for proper exposure. If the pleura cannot be pushed up out of the 
way, both layers may be sutured to the diaphragm before opening 
the cyst; or the so-called two-stage operation may be performed. In 
the latter case, gauze is packed down against the cyst and left there 
for forty-eight hours or longer to excite the formation of adhesions. 
At the end of this time the cyst is evacuated in the usual way—due 
care being taken to protect the wound edges. 
The technic for operation upon cysts of the lungs does not vary 294 
INTERNATIONAL CLINICS 
in great detail from that of cysts of the liver. The general rules 
for operating for empyema should be observed. Corlette has pro- 
posed, and employs, a technic for operating upon large hydatid cysts 
of the lungs, i.e., u evacuation of the cyst followed by immediate 
closure of the chest-wall without drainage.” He also advises the 
“ radical extirpation ” of old calcified cysts in other locations, 
with the capsule, providing the operator is an experienced man. 
Delageniere has advised the gradual production of a pneumothorax 
by opening the pleura slowly. The cyst is exposed by incising the 
lung tissue or overlying pleura, is opened after protecting the wound 
with gauze, and is then evacuated. If complete removal of the parent 
cyst is not feasible, marsupialization and packing of the cavity meets 
with very good success. Brewer injects the cavity daily with a 
solution of silver nitrate, 1:8000, gradually increasing the strength 
to 1:1000. At a later period he uses the Bier cups to hasten healing 
and to collapse the cavity. Deve sterilizes the cyst interior 
with formaldehyde. 
French literature is full of reports of operations upon echino- 
coccus cysts of the lungs. Guimbellot, in 1910 (“ These de Paris ”) 
collected 225 cases which were treated surgically, with 87 per cent, 
cures. When the suppurating cysts are excluded, the cures amount 
to 91.8 per cent. Tuffier reported thirty-five operations with but 
one death. Albertin and Barjon reported a case of two cysts of the 
right lung—one of the upper lobe near the apex, and one at the base, 
which were removed one at a time, six months apart, with recovery 
of the patient. For these operations, local anaesthetic and the patient 
in the “ jockey position ”—the so-called Lamas-Mondino technic, 
with patient astraddle of the operating table, and shoulders bent 
forward—are said to be a great advantage. Bib resection over the 
previously localized cyst is performed, the parietal pleura is opened 
and a gauze tampon is packed down against the cyst. The second 
stage, evacuation, is performed in twelve to thirteen days (Prat43). 
Drainage is usually completed at the end of two or three months. 
Hydatid cysts of bone usually require incision, evacuation 
and drainage. Where there is considerable bone destruction, a frac- 
ture, or a large joint is invaded, amputation is often the operation 
of choice. Each case presents its particular problems, and no specific ECHINOCOCCUS DISEASE 
295 
rules can be laid down which will apply to all cases. However, the 
general rules as regards the protection of the fresh wound edges, 
and thorough removal of all cyst-membrane and fluid, should be 
borne in mind. It has been said that all the elements that char- 
acterize sarcoma are present in bone hydatids except the morphology. 
The surgeon should therefore act accordingly. 
Cysts of muscles may be excised, incised and drained, or evacu- 
ated through a canula and injected with antiseptic solutions. Exci- 
sion is to be preferred. Where this is not possible, incision is done 
after protecting the wound edges. The gelatinous walls of the 
mother-cyst are curetted with gauze, and drainage is provided for. 
Echinococci of the brain, spinal cord and vertebrae have been 
successfully operated upon (Cardenal and Castella; Verco; Rennie 
and Crago; Mills and MacCormick; Tytler and Williamson). In 
the superficial cysts, good results are the rule, but in the central ones, 
the reverse is true. General rules for localization and trephining 
apply here as in other tumors of the central nervous system. 
Hydatid cysts of the kidney are treated by nephrectomy, or by 
nephrotomy with resection of the cyst where possible, and under the 
precautions above outlined. Kretschmer 34 reviews all phases of the 
surgery of echinococcus disease of the kidney, and outlines four 
methods of dealing with it in this location: (a.) Delbet’s operation, 
usually impracticable; (5) nephrotomy, justifiable where the cyst 
is very large, or the patient too weak to withstand (c) resection, or 
(d) nephrectomy. Of the eighteen American cases reviewed by 
Kretschmer, nine were nephrectomized. There was one death, due 
evidently to spilling of fluid and debris into the wound when the 
cyst ruptured. If resection of the cyst cannot be done safely, it is 
far better to do a nephrectomy. 
In the case of the spleen, there are usually so many adhesions 
that the only safe procedure is splenostomy, the lips of the incision 
in the spleen or adventitious sac being sutured to the skin. The 
defect in the abdominal wall is repaired later. According to Fowler 44 
there were only 100 cases of cysts of the spleen recorded up to 
1890, and the mortality for the twenty-three cases splenecto- 
mized up to 1908 is given as 17 per cent. Before a cure of the 296 
INTERNATIONAL CLINICS 
disease is pronounced, the liver should be carefully gone over for 
evidences of cysts of that organ. 
Cysts of the pancreas must be dealt with according to location. 
A good plan, followed by the few men who have operated upon cysts 
in this location, is to marsupialize the pericystic pouch and apply 
a mild antiseptic such as Dakin’s solution to the interior of the pouch. 
Albo 32 mentioned the use of hypodermic injections of one c.c. of 
adrenalin chloride solution to preclude the development of shock and 
anaphylaxis, both during and after the operation. 
Hydatid cysts low down in the female pelvis should be attacked 
by the vaginal route if possible, thus doing away with the chance of 
soiling the peritoneal cavity. 
In general it may be said that echinococcus cysts and colonies, 
if not too wide-spread, may be eradicated by surgery, but the disease 
is very persistent and requires patience on the part of the surgeon 
and the victim of the disease. 
SUMMARY AND CONCLUSIONS 
An effort has been made to assemble all of the important facts 
regarding echinococcus disease into one monograph. 
It is obviously a disease which is on the increase in the United 
States, and might therefore be a worthy subject for more thor- 
ough investigation. 
There is still considerable to be learned regarding the disease, 
as is shown by the fact that able pathologists and helminthologists 
disagree on the subject of the number of species of the parasite, and 
the mode of transmission of the disease to man and other second- 
ary hosts. 
With a means of specific diagnosis at our disposal, it should not 
be difficult to go through an entire community or herd and pick out 
carriers of the disease. 
The dog and, to a lesser extent, the cat are deserving of the 
gravest suspicion whenever the disease breaks out in the flock or 
herd, or becomes epidemic in man. In the segregation of dogs and 
cats lies the solution of the problem as regards prevention. 
With Iceland, Argentina, and Australia as horrible examples 
before us, we should be stimulated to an active effort to stamp out 
the disease in the United States, and prevent its further entrance. ECHINOCOCCUS DISEASE 
297 
In view of the fact that the chief characteristics of the disease 
are the same, no matter what the host, I have seen fit to illustrate 
the pathology in a number of the organs by means of photographs 
of specimens from my own case, an ape, Cynocephalus porcarius. 
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