A Canine Case with Thymoma and Leiomyosarcoma in the Urinary Bladder

Abstract

A 12-year-old female dog was shown to have spheroidal nodules on the mucosal surface of the urinary bladder by ultrasonography and a nodule at the anterior mediastinum by X-ray. Grossly, the urinary bladder wall was thickened with spheroidal nodules on the mucosal surface, and a grayish white tumor was detected at the anterior mediastinum. Histologically, the urinary bladder tumor consisted of the proliferation of atypical spindle cells stained red by Azan and was diagnosed as leiomyosarcoma. On the other hand, the tumor at the anterior mediastinum was consisted of epithelial cells forming Hassall's bodies and was diagnosed as thymoma.