Primary biliary cirrhosis associated with multiple myeloma.

An association between autoimmune disease and malignancy, in particular lymphoproliferative neoplasms, has been reported, as has an increased incidence of extrahepatic malignancy in primary biliary cirrhosis (PBC). Monoclonal immunoglobulin elevations in PBC are rare, and there have been only three cases in the literature of PBC associated with multiple myeloma. We describe a patient who was concurrently diagnosed as having PBC and multiple myeloma, and emphasize the need to consider myeloma when evaluating monoclonal gammopathy in PBC. We also discuss the possible mechanisms for the association of the two conditions.