Primary epitheliotropic T-cell lymphoma of the urinary bladder in a dog

A 7-year-old, intact female mixed-breed dog was presented for evaluation of hematuria. Physical examination revealed a suprapubic mass. Ultrasonograph ic examination showed a large lobular mass occupying the urinary bladder. A t the owners' request, the dog was euthanatized and a postmortem examinatio n was performed. Necropsy confirmed the presence of a lobular mass of about 5- to 6-cm diameter protruding into the lumen of the bladder. Histological ly, the mass was composed of a large number of atypical lymphoid cells in t he lamina propria and mucosal epithelium. Immunohistochemically, the neopla stic cells expressed CD3 but not CD79 alpha. or keratin and vimentin, suppo rting a diagnosis of T-cell lymphoma.