Bladder leiomyoma in a sheep: a rare case report

Bladder leiomyoma is benign neoplasm of smooth muscle and rarely reported in domestic animals. This tumor is most commonly diagnosed in the alimentary and urogenital tracts. This report describes the pathological characteristics of leiomyoma in the urinary bladder of a 4-year-old female sheep during routine necropsy. Urinary bladder showed that two sessile masses firm in consistency and well demarcated were located within the muscle layers and protruded from the mucosal layer. Bladder mucosa was intact. In histopathologic investigation, the masses were composed of densely interwoven bundles of smooth muscle with spindle cells. No malignancy changes including mitotic index, hemorrhage, or necrosis foci were detected. Based on the gross and microscopic findings, leiomyoma was diagnosed. To the best of our knowledge, this is the rare description of a bladder leiomyoma in sheep.