Feline lymphoplasmacytic stomatitis associated with monoclonal gammopathy and Bence-Jones proteinuria

Lymphoplasmacytic stomatitis and gingivitis was diagnosed in an 8-year old female domestic shorthair. The cat had evidence of severe generalized inflammation of the oral cavity. Biopsy samples were evaluated and displayed a lichenoid, interface stomatitis which was predominantly lymphoplasmacytic. Serum protein electrophoresis confirmed a monoclonal gammopathy. Urine protein electrophoresis confirmed Bence-Jones proteinuria. Protein electrophoresis was used to diagnose monoclonal gammopathy (the production of a monoclonal immunoglobulin, or paraprotein, which is associated with a characteristic "M" protein spike on serum electrophoresis). Diseases associated with monoclonal gammopathy are similar in the dog and cat. Alkylating agent chemotherapy is used to rapidly reduce paraprotein concentrations in multiple myeloma. Multiple myeloma is the most common disorder associated with monoclonal gammopathy. This condition is less common in the cat, compared to the dog. This report examines the diagnosis and treatment of multiple myeloma in a cat presenting with severe stomatitis.