Oviduct Adenocarcinoma in Some Species of Captive Snakes

This article reports 5 cases of oviduct adenocarcinoma in adult captive snakes from Smithsonian's National Zoological Park. This neoplasm was found in 1 of each of the following species: emerald tree boa ( Corallus caninus), Amazonian tree boa ( Corallus enydris enydris), Burmese rock python ( Python molurus bivittatus), Northern pine snake ( Pituophis melanoleucus melanoleucus), and corn snake ( Elaphe guttata). Grossly, tan to red firm masses were found within oviducts in 3 cases. In an additional 2 cases, the primary tumor was detected only histologically. Microscopically, neoplasms were papillary, and often extended transmurally. The neoplastic cells were polygonal and organized in acini or cords, with often abundant fibrovascular stroma. Hemorrhages and necrosis were present in all cases. Inflammation, myxomatous material, desmoplasia, and bacteria were often observed. Histologic evidence of metastasis was present in all cases. Solid metastases were seen in all animals except the Northern pine snake and involved several organs including the liver, lung, and heart. Emboli of neoplastic cells were observed in all animals but the Burmese rock python and corn snake.