Primary ovary hemangiosarcoma in a female dog

Abstract

A nine-year-old female Boxer was diagnosed with osteosarcoma in the right hind limb. During imaging exams to investigate the occurrence of metastasis, it was observed a mass in the abdominal cavity. A laparotomy was performed, and the mass was detected in the left ovary. Intraoperative fine-needle aspirates were made and showed spindle cells with moderate cellular pleomorphism and neutrophils. The cytological findings were not compatible with osteosarcoma metastasis. The mass was excised and submitted to histopathological evaluation. The microscopic examination showed a proliferation of spindle cells forming small vascular channels and a trabecular pattern interspersed by discrete to moderate collagenous stroma. The cells showed moderate cellular pleomorphism and high mitotic index. There was abundant necrosis and multifocal hemorrhage. The definitive diagnosis was hemangiosarcoma. This is a rare primary ovary tumor in dogs with just one previous report in veterinary literature. However, it should be considered as a differential diagnosis in female dogs with ovary mass.