Clinical presentation, diagnosis and management of primary renal leiomyoma in a dog

Abstract A 10‐year‐old, male, entire German shepherd dog was presented with a week's history of diarrhoea and abdominal pain. Abdominal ultrasound identified an abdominal mass in the area of the right kidney. A computed tomography scan revealed a large, heterogeneously contrast‐enhancing mass at the cranioventral pole of the right kidney. A right ureteronephrectomy was performed, and the patient was discharged 48 hours after surgery. Histopathology revealed a non‐encapsulated but well circumscribed neoplasm focally replacing the renal cortex and consisting of bundles of spindle cells with mild cellular pleomorphism, mild to moderate anisokaryosis, no nuclear atypia and negligible mitotic activity. A histopathological diagnosis of benign renal leiomyoma was made and confirmed with immunohistochemistry. Renal leiomyoma should be included in the differential diagnosis in dogs with renal neoplasia.