Tumors of fishes, amphibians, and reptiles.

s of other reported cases of papilloma SCHROEDERS, 1908: In several species of gudgeon Gobio the author observed "fibro-epitheliomata. " In some fish the tumors were solitary, in others multiple. In all instances they were ,sharply circumscribed, papillomatous, and yellow-white in color. JOHNSTONE, 1912 : An irregular cauliflower-like growth was observed on the snout of a halibut Hippoglossus hippoglossus, weighing 120 pounds. On section there was marked proliferation of the corium, the overlying epithelium was intact with little evidence of hyperplasia. JOI-INSTONE, 1925: About 1 dozen whitish warts, averaging 5 mm. in diameter, were scattered over the unpigmented side of a plaice Pleuronectes platessa. The growths were found to be impregnated with crystals of magnesium phosphate. The corium was thickened and showed evidence of connective tissue proliferation; the overlying epithelium was thin. JOHNSTONE, 1925 : Flat cutaneous warts were found on three plaice, Limanda limanda caught in the North Sea. One fish had a single tumor, 5 cm. in diameter, near the eye; another had multiple warts scattered over the body, and the third had 2 growths, one supraorbital and another on the dorsal fin. All of the tumors were papillomas. SAGAWA, 1925: In each, of 2 goldfish Carassius auratgs there was a wart-like tumor the size of a pea on each of the pectoral fins. The hyperplastic epithelium was arranged in papillary folds and in some areas appeared keratinized. Clavate and mucous cells were absent in the tumor, though they were plentiful in the normal skin. TAKAHASHI, 1929: In a crucian carp Carassius carass/us a tumor was located near the posterior margin of the left operculum. It was a sharply circumscribed grayish-white growth, 3 x 2 x 0.5 cm. Histologically, there was evidence of active epithelial proliferation with the formation of epithelial "pearls" and numerous mitoses. The stroma was scanty, the surrounding tissues were not invaded, and metastases were not found. After 16 months of observation the tumor appeared to be decreasing in size. A biopsy was taken and pieces transplanted to other fish; none of the transplants grew; no details were given. THOMAS, 1930: In 2 soles Soles solea similar tumors were found behind and below the opercular opening on the pigmented side of each fish. Each of the tumors measured about 35 x 20 x 7 mm. ; they were sessile and grossly lobulated; the overlying skin was devoid o f scales. Mas.sive pegs of epithelium with intact basement membrane extended deep into the subcutaneous tissue. Roentgenograms revealed that the adjacent bone was not involved. The author believed that these tuResearch. on July 22, 2017. © 1948 American Association for Cancer cancerres.aacrjournals. org Downloaded from 660 C a n c e r R e s e a r c h mors were due to chronic irritation of the po.stopercular skin by sand particles drawn into the mouth and expelled through the gill vent in the act of breathing. THOMAS and OXNER, 1930: A tumor was located on the lower lip in each of 3 eels Anguilla anguilla. The lesions showed simple epithelial proliferation with a tendency to reduplication of the basal cell layer; the basement membrane was preserved. THOMAS, 1932: A 32 cm. brown trout Salmo trutta bore an irregular tumor at the level of the posterior margin of the operculum. It measured 22 x 11 x 5 ram. , was not sharply demarcated, and in both gross and microscopic structure was a typical papilloma. COATES, Cox and S~ITH, 1938: A tumor appeared in the right mid-dorsal region of a six foot adult electric eel Electrophorus electricus caught in the Amazon river basin and maintained in good health in a fresh water tank at the N. Y. Aquarium for a period of more than four years. The growth began as a small elevation of the skin, pinkish-gray in color and a few millimeters in diameter. Its maximum size of 2 x 2.5 cm. was reached in about ten weeks, when it was excised. No recurrence took place in the remaining year and a half of life. The growth was a grape-like pedunculated mass composed of . squamous epithelium commingled with very many mucous cells. The epithelium was supported by a central narrow fibrous core of connective tissue.