Hepatic plasmacytoma and biclonal gammopathy in a cat.

A 13-year-old castrated male domestic shorthair cat was evaluated because of weight loss, despite a good appetite. The most remarkable abnormality was a total serum protein concentration of 12.4 g/dl, with a globulin concentration of 9.4 g/dl. Serum protein electrophoresis revealed a biclonal spike in the gamma region. At necropsy, 2 discrete plasmacytomas were found in the liver, without bone marrow involvement or amyloidosis.