Multiple myeloma in association with sarcoidosis.

The association of sarcoidosis with Hodgkin disease and non-Hodgkin lymphoma is well known. However, multiple myeloma also can occur rarely in association with sarcoidosis. We describe a patient with sarcoidosis who subsequently developed multiple myeloma. The patient was a 49-year-old woman with a 4-year history of severe, chronic, active sarcoidosis involving her lungs, lymph nodes, eyes, and bone marrow. During the initial clinical workup, a serum monoclonal paraprotein was detected and bone marrow examination revealed a slight increase in plasma cells (4%), in addition to noncaseating granulomas. Thus, the diagnoses of monoclonal gammopathy of undetermined significance and sarcoidosis were established simultaneously. She sought medical attention for her current illness when she developed low back pain and weakness of her lower extremities. Serum protein electrophoresis and immunofixation revealed a monoclonal paraprotein, immunoglobulin (Ig) G kappa type, and quantification revealed an IgG level of 46.67 g/L (normal, 5.88--15.73 g/L). Bone marrow aspiration and biopsy revealed multiple myeloma and sarcoidosis. Including this patient, 11 cases of sarcoidosis and multiple myeloma have been reported to date, including 3 patients with monoclonal gammopathy of undetermined significance preceding the onset of multiple myeloma. In this case, as in most of the cases reported previously, sarcoidosis preceded the development of multiple myeloma.