Schlumberger and Luck^— Tumors in Fishes 



705 



lesions suggestive of the neoplasm which he had ob- 

 sened in the pine snake. The changes occurred 

 most frequently in the Crotalidae (rattle-snakes, 

 water moccasins) and Colubridae (pine snakes, black 

 racer). The author traced the development of the 

 lesicMis to necrotic foci of unknown etiology. The 

 necrosis was apparently followed by an abortive 

 and atypical regeneration of the terminal ductal epi- 

 thelium, producing small, adenoma-like cell maases. 

 These continued to proliferate while degeneration (rf 

 acinar and islet epithelium progressed until some- 

 times the entire organ was replaced by atypical duct 

 epithelium. Whether, or at what stage, the process 

 ceases to be an atypical regeneration and assumes 

 the character of a neoplastic tumor is difficult to 

 determine. At the time of his report Ratdiffe re- 

 garded the lesions as early tumors; he has recently 

 informed us that he now considers them to be re- 

 generative rather than neq>lastic. Continuing his 

 study of this disease, he examined 261 snakes be- 

 longing to the most susceptible species, 60 to 90 days 

 after capture. In contrast to the high incidence of 

 the lesion in animals that had died in captivity only 

 ten of the sacrificed snakes showed evidence of 

 pancreatic neoplasia. 



A report by Ball (4) of a malignant melanoma 

 in each of two pine snakes Pituophis tnelanoieucus 

 has recently appeared ; we have had the opportunity 

 of examining the tumors. The animals were a male 

 and a female, kept in the same cage at the San 

 Diego Zoological Gardens. In the female snake a 

 dark rapidly growing tumor was noted on the tail 

 after the animal had been in captivity for three 

 years. The tail was amputated, but subsequently 

 two black tumors appeared on the head and one on 

 the abdomen. Two years after the primary tumor 

 was first noted, a fusiform swelling developed anter- 

 ior to the cloaca. Thb increased in size and the ani- 

 mal died six months later. At autopsy the tumor 

 measured 11 x 6 x 5 cm. and had encroached on the 

 coelomic cavity. Two metastatic nodules, approxi- 

 mately 2 cm. in diameter, were found in the liver. 

 Histologically the neoplastic cells were spindle 

 sb^)ed with an abundant cytoplasm that frequently 

 contained large numbers of fine pigment granules. 

 The cells were arranged in interlacing bundles; the 

 nuclei occasionally showed some evidence of palisad- 

 ing. 



In the male animal a tumor was first note<l after 

 almost six years of captivity. The growth, which 

 appeared on the upper Ubial fold, increased very 

 rapidly in size and the snake was sacrificed 8 mooUis 

 after the tumor was first seen. Htstologicany it re- 

 sembled that of the first animal and was identified at 



a melanoaraNiia. No metaftaset were fond. How- 

 ever, a Boo-pigineiitcd tumor 1.S cm. ia dlHHlcr 

 was diacofvered on the palate. It was f«?ff!p«ff<| of 

 large finngafcd cells with a fibrillar cytofilam la 

 which croas striations were occasiooaUy sen. Scat- 

 tered through the section were plomp giaat oeUf 

 with multiple, centrally located nuclei TUs tomor 

 unquestionably was different from the others; it had 

 all the structural characteristics of a rhabdomyoma. 



The melanomas of the pine snakes lend added 

 interest to our recent findings of similar neopbaait 

 in two reticulated pythons, Python retiadahu. The 

 first python* was a female, 18 feet in length, and 50 

 to 60 years of age, which had been on eifaihttion in 

 the National Zoological Garden of Washington, D. 

 C, for thirteen years, when a nodule the sise of a 

 walnut was noticed on the left Uteral surface of the 

 trunk. It was located halfway between the head and 

 tip of the tail. During the following year the tumor 

 grew rapidly, and when examined l^ us measiued 

 1 1.5 X 8 X 3.5 cm. (Fig. 65). The maii waa a varie- 

 gated red-brown in color; the surface was faintly 

 lobulated. The periphery was covered by expanded 

 scales, but toward the center these were destroyed 

 by a shallow ulceration. The tumor was quite vas- 

 cular and bled profusely when we renaoved snaUl 

 portions for examination. It was firm in consb- 

 tency ; on section the surface was a mottled red, yel- 

 low, and black. Six months later the tumor had in- 

 creased somewhat in size and the area of ulceration 

 was larger. The animal was killed as unfit for exhi- 

 bition. 



At autopsy the tumor was found to have pene- 

 trated to the vertebral bodies. Its lateral spread had 

 been somewhat restricted by the stout connective 

 tissue septae that normally separate the larger 

 muscle hundlea (Ftg. 64). Protruding into the coel- 

 omic cavity 20 cm. caudal to the heart, was a bbcfc, 

 broadly sessile mass that measured 7x5x6 cm. 

 (Fig. 66) and waa covered by smooth transparent 

 mesothelium. On section it was granuUr, bbcfc in 

 color, and the pigment it contained rubbed off and 

 discolbred the fixing fluid. On the dorsal surface of 

 each kidney were 6 to 7 widely scattered, rougMy 

 circular, umbilicated, yellow-white nodalcB 

 from 0.5 to 1.2 cm. in diameter (Ftg. 65). 



Histologically the primary neoplaaa 

 poaed of intertadng bundles of ipiiidb 

 (Fig. 67) which in some areas cwnHlii s d Urfe maa- 



• Wc wbh to cxprtM ear i p pwd u ba to Dr. W. M. 

 Msaa, dkcctor of the NAtkind TmlmirsI Owrtfm, for piK- 

 li« tUsoaiMl aod ibr tsdliiin of tiw Mplfc Hmm at oar 



