Waldenström's Macroglobulinaemia with Ig E M‐Component

A case of Waldenström's macroglobulinaemia with Ig E M-component was presented. A 76-year-old Japanese woman had a history of the operation for mammary carcinoma. Although neither lymphadenopathy nor hepatosplenomegaly was present, the immunohaematological findings typical for Waldenström's macroglobulinaemia were observed in this patient. Coexistence of the Ig M and Ig E M-components was recognized in the patient's serum protein. Positive reaction for FITC-conjugated anti-epsilon or rhodamine-conjugated anti-mu was noted in proliferating lymphoplasmacytic cells of the patient's bone marrow, but these reactions were not simultaneously observed in a single cell. The finding suggests that two separate populations of M-component-producing cells were present.