Morphology of canine ovarian Sertoli-Leydig cell neoplasms. A report of 12 cases.

Of 71 dogs with primary ovarian neoplasms, 12 (17%) had Sertoli-Leydig cell tumors. Five dogs had Sertoli-Leydig cell tumors, four had pure Sertoli cell tumors, and three had Sertoli-Leydig cell tumors with a retiform pattern. Variously differentiated Sertoli cells were seen in the Sertoli-Leydig cell tumors, and one of these metastasized to the peritoneum. The pure Sertoli cell tumors were similar to these tumors in male dogs. The retiform pattern in the third group of tumors was characterized by tubuloalveolar structures resembling rete testes. Heterologous elements were seen in seven tumors (58%)--enteric glands in three Sertoli-Leydig cell tumors and one Sertoli-Leydig cell tumor with retiform pattern, and neuroendocrine carcinoma in one pure Sertoli cell tumor and two Sertoli-Leydig cell tumors with retiform pattern. The uterus was examined in seven dogs, and six (87%) had endometrial hyperplasia.