Complex IgA gammopathy in Gaucher's disease.

A 55-year-old Jewish patient was simultaneously diagnosed as having Gaucher's disease and IgA multiple myeloma. Serum protein electrophoresis and immunoelectrophoresis showed two different IgA kappa type monoclonal spikes. After four years of observation, a rapid fatal course of disease developed together with expression of J chain protein and an additional IgA lambda paraprotein. Although dysproteinaemias and multiple myeloma have occasionally been reported in Gaucher's patients, such a complex gammopathy has to the best of our knowledge not yet been described.