Macroglobulinemia-myeloma double gammopathy. A study of four cases and a review of the literature

The coexistence of macroglobulinemia and myeloma type M components in the same serum is very rare. The following features were observed in four patients with this condition: (1) Hyperviscosity syndrome with widespread amyloidosis and foci of calcification; the serum contained an IgG4(κ), 7S and 17S IgM(κ) M components. (2) Polyarthritis, high fever, lymphadenopathy, hepatosplenomegaly and skin rash; IgA(λ) cryoglobulin and IgM(λ) pyroglobulin were found in the serum. (3) Plasmacytoma of the liver; IgG(λ) and IgM(λ) were detected. (4) Malignant lymphoma of a diffuse histiocytic type; IgG(κ) and IgM(κ) were present in the serum. A review of the literature disclosed 26 other examples of macroglobulinemia-myeloma type double gammopathy. The clinical picture, well described in 17 of these, was heterogeneous and not necessarily typical of either condition. Whereas some investigators stated that each M component was produced by a distinct population of malignant cells, others presumed that the same clone was capable of synthesizing more than one immunoglobulin.