Acute myelomonocytic leukemia in a patient with macroglobulinemia and malignant lymphoma

Acute myelomonocytic leukemia occurred in a 69-year-old man with malignant lymphoma and macroglobulinemia. Fluorescent staining demonstrated the macroglobulin in plasma and leukemic cells. Plasma cells seemed to be producing paraproteins, while leukemic cells appeared to be engulfing them as seen with transmission electron microscopy. The sequence of events ruled out the possibility that myelomonocytic leukemia developed following the use of cytotoxic drugs. The case presented in this report is a rare example of malignant lymphoma, macroglobulinemia, and acute myelomonocytic leukemia occurring in the same patient.