Résumé
A 12-year-old castrated male Persian cat presented with abdominal distension, anorexia, and no defecation. The radiography revealed ascites, pleural effusion, and a cranioventral mediastinal mass. Ultrasonography showed a well-defined mass lesion within a thickened ileal segment with a transmural loss of layering and multiple hyperechoic nodules arising from the peritoneum. Computed tomography showed peritoneal thickening with contrast enhancement, a bulky heterogeneous ileal mass, and mesenteric involvement with diffuse nodules. An alimentary lymphoma was confirmed by fine needle aspiration of the small intestinal mass. Peritoneal lymphomatosis is rarely reported as a metastatic manifestation in veterinary medicine. This report describes the imaging features of lymphoma with peritoneal lymphomatosis in a cat.