Schlumberger and Luck6 — Tumors in Fishes 



699 



tadpoles (19, 22), and studied in tissue culture 

 (117). The frog being poikilothermlc lends itself 

 particularly well to studies on the effect of tempera- 

 ture on the tumor as regards its rate and manner of 

 growth (121), and as regards induction and aug- 

 mentation of metastasis (123b). These experimental 

 investigations are reviewed elsewhere (123a). Here 

 it must suffice briefly to mention a few other studies 

 to indicate the lines of research that have been pur- 

 sued. Witschi (232) and Briggs (18, 20) have 

 studied the abnormal growths which appear in tad- 

 poles that develop from overripe eggs. Briggs (21) 

 has also investigated the effect on development of 

 eggs exposed to carcinogens, and has introduced 

 carcinogens into tadpoles (17). Duran-Reynals 

 (41) and Schlumberger (176a) have injected sev- 

 eral carcinogens into adult frogs. 



To the cases reported in the literature two ad- 

 ditional anuran tumors may be added. One tumor 

 occurred in a second-year tadpole of the green frog 

 Rana clamitans. It formed a mass measuring 7x5 

 X 6 mm. on the dorsal fin, parts of which were de- 

 stroyed by the growth (Fig. 45). Sections revealed 

 that portions of the dorsal myomeres had been in- 

 filtrated and destroyed (Fig. 49). Histologically 

 the tumor had the structure of myxosarcoma, being 

 composed of large stellate and spindle shaped cells 

 which were embedded in an abundant mucinous 

 matrix (Fig. 47). No inflammatory reaction was 

 present. The growth corresponded in every way to 

 a true neoplasm. The tumor is unique in that no 

 neoplasms in larval amphibians have been recorded. 



The other tumor occurred in an adult bullfrog in 

 iddch it formed a swelling in the left flank. On dis- 

 section, the growth was found to measure 2x1x1 

 cm. It probably had its origin in one of the nerves 

 of the sacral plexus. It protruded into the coelomic 

 cavity, and through the muscles of the back which 

 it had invaded and partly destroyed ( Fig. 48 ) . His- 

 tologically, the mass was composed of interlacing 

 bundles and whorls which resembled neoplastic con- 

 nective tissue (Fig. 49, 50). In general appearance 

 the tumor was similar to the more malignant nerve 

 sheath tumors of man. 



AbaCractJi of oUmt reported cmw of •nnrsR tunors 



Ebekth, 1868: About 60 nodules, sm.ill but varying 

 in size, were found on the dorsal and ventral surfaces 

 of a frog. The tumors were located in (be corium. were 

 covered by an intact epithelium, and did not infiltrate 

 the adjacent tissues or metastasixe. Histolofically the 

 tumors were composed of stratified squamous epUhdhnn 

 arranged to form tubules and acini that superficially 

 resembled the normal skin glands. Ebtrth di.Kusscd the 

 possible relation of parasites to the neoplasms, since 



trematodes and nematodes frequently inhabit the cu- 

 taneous glands of frogs. TranqpUnuUon 'f|miiff'rMr 

 yielded negative results. 



Orucaobs, 1898: The left femur of a Irof Rma 

 w€scms presented a spindle shaped tmeOk^ that oc- 

 cupied the entire length of the femur and reached a 

 maximum dbmeter of 8 ami. The ptTHtwi «m in- 

 tact Histologically the tumor consisted of tmbecniae 

 of bone and cartilage surrounded by laife spaces. In 

 the latter were rapidly proliferating mononuclear ccUs 

 that appeared to be derivatives of the bone marrow. 

 The author concluded that the Icmb «m a **aednOMy 

 osteosarcoma." However, the desariptioB ii mom mv- 

 gesUve of callus fonnation after fracture. Ifnnnjr (141) 

 described a similar lesim in a frog and concluded that 

 it probably represented callus rather than bone tumor. 



Vaillant and Prmr, 1902: In their report of a 

 tumor in a python the authors briefly mention a fibroma 

 which they found in a frog, Rana etctienU. The (lonor 

 originated in the buccal cavity and protruded from the 

 mouth. 



SifALLWooo, 190S: Bilateral renal tumoa were 

 found in a leopard frog Roma pifient and were inter- 

 preted as having arisen in the adrenab and secondarily 

 invaded the kidneys. Histologicany the tumor was com- 

 posed of cuboidal or columnar epithelial cells arranged 

 as dilated and tortuous tubules, into the lumens of 

 which the neoplastic cells often extended as papillary 

 projections. This tumor was first reviewed by Murray 

 (141) who failed to see any resemblance between the 

 tumor cells and those of the normal adrenal S«d>se- 

 quently one of us (112) obtained a slide of the tumor 

 from Dr. Smallwood. A study of thl^ section revealed 

 that the lesion was a renal adenocardnoroa and bore no 

 relation to the adrenal ^ands. 



Plehn, 1906: Between the ovaries and fat bodies of 

 Rana esculenia were bilateral iriiite cherry-siKd tumors; 

 5 or 6 smaller nodules were scattered among the eggs 

 in the ovaries. The neoplastic cells were Urge, pleo- 

 moq^c, with vesicular nuclei: multinucleated giant 

 cells were conunon. Normal and abnormal mitotic if* 

 ures were abtmdant. PMm believed that the tumors 

 were carcinomas and represented a neoplastic growth 

 of the primitive eug cells. 



MrRKAV, 1908: A hemispherical nodule was present 

 on the inner aspect of the thigh of an adult male frog. 

 The overiying skin was stretched, but apptmily intact. 

 The neopUstic squamous epithelial cells formed irregu- 

 br tubules and acini separated by delicate coimecttve 

 tissue septae. The epithelium res em bled that leca by 

 Eberth in the benign adenomas. In tUs case. Iwntvcr. 

 the structures were moie Uaam and tiM su b j acan t 

 muscles were infiltrated by the tmor cdh. Monay 

 repirded this growth and another limflar one at adeno- 

 cardnoroa* of the skin. 



Pavu>vbky, 1912 : The author presented two cases of 

 adenoma and one of adenocarcinoma of the sUn in 

 frogs at a mectlnc <rf the RuAtian Pa th ohg ical Society. 

 The tumon were similar in that the nsoplaHlc tuhuhis 

 comrotmlcated with the surface and were Uned hy taU 



