Malignant ovarian teratoma in a red-eared slider (Trachemys scripta elegans)

A 7-year-old intact female red-eared slider (Trachemys scripta elegans) presented with anorexia of 2-3-weeks duration. Coelomic radiographs demonstrated 3 shelled eggs in the right cavity. Hormone therapy failed to induce oviposition. Exploratory laparotomy revealed 3 calcified eggs in the right oviduct and a large mass obliterating the left ovary. The large, multilobulate mass had scattered, firm, white nodules and weighed 450 g. Histopathology revealed a malignant teratoma composed of immature embryonaland extraembryonal elements derived from all 3 germ layers with multifocal epithelial anaplasia. This is the first report of a teratoma in chelonian gonadal tissue. Teratomas and reptilian gonadal neoplasia are reviewed.