Primary extraskeletal hepatic osteosarcoma in a cat

A 13-year-old spayed female domestic shorthair cat with an abdominal mass was evaluated; radiography revealed a radiopaque mass in the cranioventral region of the abdomen. A celiotomy was performed, and the mass was identified histologically as a hepatic osteosarcoma. Complete remission of the tumor was accomplished after partial hepatectomy and adjuvant treatment with carboplatin.