Human asymptomatic/smoldering Waldenstrom's macroglobulinemia-like condition in a dog

Abstract

An asymptomatic 11-year-old castrated male Labrador Retriever was referred for a further investigation of prolonged hyperglobulinemia with IgM monoclonal gammopathy. On the day of presentation at the receiving hospital, physical examination was unremarkable. Nevertheless, bone marrow cytology demonstrated an increased proportion of lymphoplasmacytic cell. A comprehensive screening did not confirm possible gammopathy-producing diseases. The combination of the bone marrow infiltration of lymphoplasmacytic cells and the sustained monoclonal IgM gammopathy was consistent with an asymptomatic/smoldering Waldenstom macroglobulinemia. The dog has remained asymptomatic, and has survived for over 3 years. As in people, asymptomatic/smoldering WM is a differential diagnosis for hyperglobulinemia in dogs.