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Cancer Research 



columnar epithelium of embryonal type; these cells did 

 Dd resemble those normally found in the serous or 

 mucous glands of the frog's skin. In the case identified 

 as an adenocarcinoma the tumor cells invaded the sur- 

 romdiog connecti%T tissue. 



GutL, 191 J: A tumor, about the size of a cherry, 

 projected ventrally from the hilom of the left kidney 

 in an adult female Ro/ta escuUnta, The growth was 

 round, firm, red-brown, with a slightly uneven surface. 

 The neoplastic cells were pleomorphic, with large nuclei, 

 and resembled those of the adrenal. This appearance was 

 hei^tened by their occasional arrangement as cords of 

 ceUs; no glycogen, chromaAn, or fat was demonstrated. 

 Carl identified the lesion as a malignant adrenal tumor; 

 no metastases were found. Attempts to transmit it were 

 UBSuccessfuL 



Pentiiialu, 1914: Scattered over the skin of the 

 trunk and extremities of a frog were 24 nodular ade- 

 nomas, the largest of which was the size of a small pea. 

 The overl>'ing skin adhered to some, over others it was 

 ulcerated; the cut surfaces of the tumors were very 

 bloody. Histologically the neofdasms were adenoma- 

 tous, with frequent papillary proliferations extending 

 into the cysts. No metastases were found; transplants 

 failed to grow. 



Sechzx, 1917/19: An irregular cauliflower-like mass 

 about 1 cm. in diameter was present on the outer sur- 

 face of the thigh in Rana esculcnta. The tumor re- 

 sembled those described by Murray, though it was less 

 infiltrative and apparently benign. The neoplastic epi- 

 thdial cells were arranged as solid sheets or acini; the 

 btter occasionally became small c>'sts. No meta5tases 

 were present; parasites could not be found. 



Masson and Schwartz, 1923: Three tumors, ranging 

 from 5 to IS mm. in diameter were located on the right 

 thii^, the right flank, and the lower right abdomen of 

 Rmta esculenUi. They were spherical, pale pink in 

 color, finnly attached to the epiderm but not to the 

 subjacent musculature. Columnar neoplastic epithelial 

 cells lined tubular spaces and were supported by a layer 

 of cuboidal cells. Some of the tubules were cystically 

 dilated; elsewhere the cells formed solid strands. The 

 connecti\T tissue stroma was infiltrated by inflammatory 

 and neoplastic cells which in some instances had pene- 

 trated as far as the endothelium of the ^-mph sacs. 

 The writers were undecided whether the tumors were 

 multicentric in origin or if a single one was the primary 

 growth, the others secondary. Transplants did not grow. 



VoLTcxiA, 1928: A firosarcoma had produced con- 

 siderable swelling of the left hind foot in an exotic frog 

 Ctrgtopkrys omaUL The tumor was dense, white, and 

 h o m og e n eous in appearance; the overling skin wns 

 ukemted; the bones of the foot were largely destroyed. 

 Numerous metastatic nodules were present in the liver, 

 two of them were as lanre as hazel-nuts. The neoplastic 

 cdb were spindle-shaped elements gathered into com- 

 pact bundles: in many places the ceUs extended to the 

 endothelial lining of the vess^. Mitoses were abund- 

 ant, and frequently atypical. 



DUANY, 1929: Two cutaneous tumon were found m 



a bullfrog Rana cateshiatia that had been brought to 

 Havana some years before from the United States. 

 The smaller growth, about the size of the frog's eye, 

 was situated between and slightly behind the eyes. Di- 

 rectly back of this was another tumor as large as the 

 animal's head. The neoplastic epithelial cells formed 

 tubules that somewhat resembled the normal skin glands; 

 the underlying tissues were not invaded. No metastases 

 were found in the viscera, but the author raised the 

 question whether the smaller nodule may have been a 

 metastasis or extension from the larger tumor. He 

 identified the tumor as an adenocarcinoma and noted its 

 similarity to those described by Murray and by Masson 

 and Schwartz. 



Gheorchiu, 1930: The author found a tumor the 

 size of a nut in the right gastrocnemius muscle of Rana 

 esculenta. The lesion involved the skin, was soft in 

 consistency, and dull white in color. The cells were 

 pleomorphic, though in some areas those of spindle 

 shape predominated. Filaria as well as numerous bac- 

 teria were found throughout the sections. The tumor 

 was easily transplantable and had been carried through 

 12 generations. About 80 per cent of the grafts "took"; 

 they grew rapidly for from 15 to 20 days, then ulcerated, 

 and the frogs died, probably from infection. The nature 

 of these tumors is questionable; it is quite possible, as 

 Cramer (32) pointed out, that the "tumors" were in- 

 fectious granulomas. 



Downs, 1932: A yellow-brown tumor almost filled 

 the coelomic cavity and compressed the liver of Rana 

 pipiens. The mass was cystic and surrounded a large 

 part of the intestine. The neoplastic epithelial cells 

 formed bizarre tubules which were identified as of in- 

 testinal origin. A section of the tumor was examined by 

 one of us (112) and a striking resemblance to the renal 

 adenocarcinoma noted. That the lesion was actually 

 such a tumor is highly probable since remnants of kid- 

 ney tissue were seen in the section. 



PiRLGT and Welsch, 1934: The authors found 17 

 cases of cutaneous adenoma amcmg 1800 frogs Rana 

 fusca. The tumors were frequently multiple and varied 

 in diameter from 1 to 15 mm. Stratified columnar epi- 

 thelial cells with large vesicular nuclei lined the irregu- 

 lar acini. Mitoses were numerous, but the basement 

 membrane was intact and there was no evidence of local 

 invasion or metastasis. Another growth observed by 

 these investigators was a 15 x 7.5 mm. tumor adherent 

 to the overlying skin of the leg in Rana fusca; the 

 femur was intact. Masses of spindle-shaped connective 

 tissue cells alternated with regions that were relatively 

 acellular, and composed chiefly of fibrils. Islands of 

 cartilage were present. In some areas a transition from 

 connective tissue to cartilage was apparent. Three frogs 

 were inoculated with the tumor tissue; in all there was 

 a severe inflammatory reaction associated with resorp- 

 tion of the implant. These authors identified this tumor 

 as a myxofibrochondroma. but their description leaves 

 one in doubt as to the nature of the growth. 



Willis, 1948: A solitary white tumor, 3 cms. in 

 diameter, was found in the liver of an adult European 



