Coexistence of myelomonocytic leukemia and monoclonal gammopathy or myeloma. Simultaneous presentation in three patients.

The coexistence of monoclonal gammopathy or myeloma and nonlymphoblastic leukemia is reported in three untreated patients. One patient had IgG kappa myeloma and monoblastic leukemia, whereas the two others had IgA paraprotein in association with chronic granulocytic and acute myelomonoblastic leukemia, respectively. Simultaneous presentation of monoclonal gammopathy or myeloma and nonlymphoblastic leukemia is rare, and this report reviews the possible pathogenesis of this phenomena.