Ovarian granulosa cell tumors (GCTs) are common neoplasm in domestic animal that originates from the sex-cord stromal cells of the ovary. The aim of present paper was to report a case of ovarian granulosa cell tumor in a 6-year-old female German shepherd and to describe the histopathological pattern of this tumor. The dog with history of clinical signs such as ascites, bloody discharge from the vulva and vulvar swelling was referred to the veterinary hospital of Tehran university. Ovariohysterectomy was done and the surgically removed ovarian masses were prepared for histopathological studies. Macroscopic and microscopic studies in this case are discussed and histopathological examination confirmed ovarian granulosa cell tumor.

Key words: Granulosa cell tumor, canine, sex-cord stromal tumor, call-exner bodies.