A case of intravascular lymphoma with mixed lineage antigen expression in a cat.

A 3-year-old neutered male British shorthair cat was presented to the Clinic for Small Animal Medicine, Internal Medicine and Clinical Pathology, at the Justus-Liebig-University Giessen with a short history of lethargy, severe dyspnoea, fever, anaemia, thrombocytopenia and hyperbilirubinaemia. In blood smears and lymph node aspirates, large pleomorphic lymphatic blasts were detected. On necropsy splenic infarcts and moderate hydrothorax as well as moderate ascites could be observed. Histological examination revealed large numbers of lymphoid blasts within the lumen of the vessels of the lung, lymph nodes, the liver, the chorioid coat of the eyes, in meningeal vessels, arteries and veins of the brain, and within the larger splenic vessels. Neoplastic cells immunohistochemically stained positive for CD45R and CD3. Based on these findings, an intravascular lymphoma was diagnosed.