Occurrence of acute monocytic leukemia in a case of untreated Waldenström's macroglobulinemia.

Acute myeloid leukemia is a rare complication of untreated Waldenström's macroglobulinemia. Although two such cases have been reported, occurrence of acute monocytic leukemia, FAB M5b subtype, in a patient with untreated Waldenström's macroglobulinemia has not been reported. The patient had distinct foci with clear demarcation of lymphoid infiltrates and myeloid infiltrates in the bone marrow, representing Waldenström's macroglobulinemia and acute monocytic leukemia, indicating the concurrence of two primary malignancies. Copyright 2002 Wiley-Liss, Inc.