Granulosa-theca cell tumors arise from the sex cordstromal tissue within the ovary. These tumors represents the most common ovarian tumor in horses but are very rarely reported tumors in birds.
The aim of the case is to describe a granulosa-theca cell tumor incidentally found in a 9-year-old female budgerigar (Melopsittacus undulatus).
The bird was brought to the clinics with complaint of anorexia, depression, hyperpnea and abdominal distention. Ventro-dorsal abdominal radiographs revealed a large, radiopaque mass in the abdomen. Postoperative death occurred, the animal was referred to pathology department and a complete necropsy was performed.
A large mass attached to the ovaries and adherent to the ventral surface of the liver was found in the abdomen (Figure 1). Grossly, the tumor was cauliflower-like, covered with a glistening capsule, yellowish, and solid with a friable to firm consistency and a 2x3x1 cm size.
Histologically, the mass was composed of polyhedral to round cells with hypochromatic vesicular nucleus and acidophilic cytoplasm. The cells formed trabecular and follicular arrangements separated by a prominent stroma and many of them contained cytoplasmic vacuoles (Figure 2). There were areas of degeneration in the islands. Mitotic figures were low and polynucleated tumor giant cells were reported. The tumor was diagnosed as Granulosa-theca cell tumor. In addition, neoplastic cells were infiltrated in the spleen.
Despite being very rare in birds and firstly described in our country, Granulosa-theca cell tumors should be included in the differential diagnosis for an abnormal abdominal distention in birds.