7QP 



Cancer Research 



bers of pigment granules (Fig. 68). Elsewhere, the 

 cells were less elongated and the nuclei more vesicu- 

 lar, with prominent nucleoli; this appearance was 

 moat marked in the metastatic nodtiles in the kidney 

 (Hg. 69). Occasionally there was a suggestion of 

 ptflffirfit^ (Fig. 70) similar to that observed in the 

 melanontas of the pine snakes. This resemblance of 

 reptilian melanomas to the neurilemmomas of man 

 may therefore perhaps be traced to the origin of 

 both in neurectoderm. 



In view of the successful transplantation of mouse 

 tumors to the yolk sac of the chick embryo (201), 

 the finely minnd python tumor was inoculated into 

 the yolk sac or onto the chorio-allantoic membrane 

 of 80 embryos. The chick embryos all died within 

 48 hours after inoculation; in some, death was the 

 result of bacterial infection; in others, the snake tis- 

 sue appeared to be to.xic to the embryo.* 



The second python, also a female, was 20 feet 

 long, and had been at the Philadelphia Zoological 

 Garden for 20 years. No information as to age is 

 avaQaUe, oth«- than that the snake was "full- 

 grown'* when received at the Garden. About a year 

 before its death, the keefsers noted a swelling in the 

 right side of the upper jaw, and two black tumors 

 oo the body. The snake became weak, declined 

 food, and had to be sacrificed.** At autopsy, the 

 tumor was found to arise from the region of the 

 an^ of the jaw; it extended forward, was covered 

 eitemally by unbroken skin, had a firm consistency, 

 and measured 6x3x2 cm. The cut surfaces of the 

 tumor were pale and had a fibrous appearance. A 

 mood tumor, 2x2 cm. in diameter, was located on 

 the side of the body, about 8 feet from the tip of the 

 tail. It was somewhat elevated, the covering skin 

 was unbroken; its consbtency was relatively soft 

 and its color deep black. A similar, much smaller 

 growth, 0.5 cm. in diameter, was found under the 

 akin about 4 feet from the head. None of the tumors 

 had invaded the neighboring tissues, and no metas- 

 tMca were found. Hbtologically, the tumors were 

 rompoted of ipindle-shaped cells, grouped in inter- 

 lacing bundlca. Mdanin was fairly abundant in the 

 two smaller growths, but the tumor of the jaw was 

 afanoat amdaootic The tumors were regarded as 

 multiple ooQ-maligiiaiit melanomas. Attempts to 

 transplant them into the anterior chamber of the eye 

 of a number of alligators, turtles and frogs were 

 mncocKful. 



Two other reports of tumori of pythons belonging 

 to a dillerent spcdes are on record. Bland-Sutton 

 (12) observed in a python Python sebae which was 

 dHUoycd at the London Zoological Garden that the 

 viionm mtxt studded with an enormous number of 



firm yellow-white tumor nodules. The liver con- 

 tained many similar nodules, varying from the size 

 of a pea to that of a large walnut. In the lung were 

 twenty pea-sized nodules; each kidney bore a mass 

 the size of a walnut, and the ovaries were the seat 

 of several that had attained the size of an orange. 

 Histologically the tumor was identified as a "medul- 

 lary cancer made up of alveoli containing masses of 

 irregular cells." The source of the metastases could 

 not be determined with accuracy, but the author 

 believed that the ovaries were probably the primary 

 site of the tumor. 



More difficult to interpret is the case recorded by 

 Vaillant and Pettit (222) in a python Python sebae, 

 which died 8 days after a swelling near the middle 

 of its body first became apparent and about 40 days 

 after the animal had become indifferent to food. At 

 autopsy a spheroidal mass that measured 28 cm. in 

 diameter was found attached to the gastric mucosa 

 and extending into the esophagus. The tumor ap- 

 parently precipitated intussusception of the small 

 intestine by the pyloric end of the stomach, account- 

 ing for the rapid increase in size of the swelling and 

 the death of the snake. The neoplasm was very 

 cystic; though most of the cysts were quite small, 

 one or two contained almost a liter of foul purulent 

 fluid. Connective tissue septae separated the cysts 

 which were often lined by epithelial celk. The na- 

 ture of this tumor is not recognizable from the 

 authors' description. It may perhaps represent a 

 cystic adenoma, but it may not be a neoplasm. Less 

 difficult to interpret are two older reports of "tu- 

 mors" in pythons (79, 224). In these cases the 

 growths were almost certainly not true neoplasms; 

 rather, they were probably organized blood clots. 



In contrast to the questionable nature of these 

 growths is the carcinoma of the kidney reported by 

 Patay (145a) in a ring-snake, Tropidonotus natrix. 

 The animal was a female, 75 cm. in length. The left 

 kidney measured 4 x 2.5 cm. Its lower portion was 

 occupied by a well circumscribed growth, approxi- 

 mately one-third the size of the entire organ. His- 

 tologically, the tumor consisted of atypical epithelial 

 cells which in some areas were arranged as acini into 

 which papillary projections protruded; elsewhere 

 the cells were undifferentiated. The author regarded 

 the tumor as a papillary adenocarcinoma, and 

 likened it to similar tumors in mammals. 



* Thb work was carried out for us through the courtesy 

 of Col. Raymond Randall, director of the Division of Veteri- 

 nary Medicine, Army Medical Center, Washington, D. C. 



** Dr. Herbert Ratcliffe, Pathologist of the Philadelphia 

 Zoological Garden, kindly gave us the snake for elimination. 



