Biclonal IgA and IgM gammopathy in lymphocytic lymphoma

We report the case of a 76-year-old white man with a diffuse, well-differentiated lymphocytic lymphoma at the base of his tongue. Although serum electrophoresis, immunoelectrophoresis, and immunofixation showed he had a biclonal IgA kappa and IgM kappa gammopathy, biopsy of the tumor showed a positive immunoperoxidase response only for IgM kappa. The biclonal pattern persisted after chemotherapy, despite shrinkage of the tumor mass. The association of IgA and IgM appears to be the least frequent combination of separate biclonal immunoglobulins, the clinical course of such patients being more often that of lymphoma or macroglobulinemia than of myeloma. However, the symptomatology can be highly variable, as our case uniquely demonstrates.