Sarcoidosis and immunocytoma.

The current literature contains reports of sarcoidosis with polyclonal increases in immunoglobulins. There are also reports of lymphoma in patients with pre-existing sarcoidosis. This is believed to be the first report of a patient in whom a monoclonal IgM kappa paraproteinemia developed after the diagnosis of sarcoidosis. This paraproteinemia was linked with a histologically proved non-Hodgkin's lymphoma. The possible relationships between the two disease entities are discussed.