A ten year old male, recently castrated Golden Retriever presented to the Cornell University Hospital for Animals Oncology Service for evaluation following removal of a testicular mass. The referring veterinarian had noted an indurated right testicle and firm spermatic cord on routine physical exam, and performed a routine castration. Histopathology showed a poorly differentiated neoplasia.

On presentation to Cornell, physical exam revealed an irregular, firm, scrotal mass and signs of chronic skin disease. Histopathologic slide review of the removed testicle was consistent with a mesothelioma. At surgery, abnormal tissue was found to continue from the scrotum along the spermatic cord through the inguinal ring, and involved the testicular artery and vein in the abdomen. The abnormal tissue was dissected out as completely as possible, and submitted. Histopathology and immunochemical staining confirmed the diagnosis of mesothelioma of the tunica vaginalis.

Follow-up therapy with intracavitary cisplatin therapy several months later was cancelled due to ultrasonographic evidence of metastatic disease throughout the peritoneum.