Cat peeing outside litter due to uterine T-cell lymphoma

Abstract

CASE DESCRIPTION A 14-year-old ovariectomized domestic shorthair cat was evaluated because of periuria and perineal licking of 3 days' duration. CLINICAL FINDINGS On initial examination, an abdominal mass was palpable cranial to the urinary bladder. The perineal area was soiled with a blood-tinged mucous fluid. Abdominal ultrasonography revealed a vascularized, focal, and circumferential thickening of the right uterine horn, involving particularly the muscular layer. No evidence of dissemination was noted. TREATMENT AND OUTCOME Hysterectomy was performed, revealing a localized, 2.5 × 4-cm firm mass with a smooth surface within the right uterine horn. Results of histologic examination and immunohistochemical analysis of tissue samples from the mass suggested high-grade T-cell uterine lymphoma. Owners declined medical and chemotherapeutic treatments. One year later, the cat developed diabetes mellitus, which was medically treated. Nineteen months following the uterine lymphoma diagnosis, a central corneal ulcer associated with a right retrobulbar mass was diagnosed. The cat was euthanized, and the retrobulbar mass was removed. Immunohistochemical staining revealed evidence of high-grade B-cell retrobulbar lymphoma. CLINICAL RELEVANCE The clinical outcome of this cat with uterine lymphoma was favorable for 19 months after diagnosis, with no treatment other than hysterectomy. Whether the same outcome could be expected for other cats with this rarely reported neoplasm remains to be determined. Uterine lymphoma should be considered as a possible cause of dysuria in an ovariectomized cat.