Abstract

The clinical, pathological, and immunohistochemical findings associated with a vaginal leiomyosarcoma in a 12-year-old, Senepol breed of cow from Uberlandia, Minas Gerais are described. The animal had a large ulcerative neoplastic growth that originated between the base and the left-lateral vaginal wall. Histopathology revealed a tumor formed by muscle-like cells that demonstrated cellular pleomorphism, anisokaryosis, prominent and multiple nucleoli, with rare tumor giant cells. The neoplastic growth invaded adjacent adipose tissue, and contained areas of hemorrhage with discrete accumulations of inflammatory cells. By immunohistochemistry, most neoplastic cells expressed actin, while immunoreactivity to desmin was weakly expressed. These findings support a diagnosis of leiomyosarcoma, and represent the first description of a bovine vaginal leiomyosarcoma from Brazil.