Expression of monocytic and T-lymphocytic phenotype in a variant form of acute promyelocytc leukaemia (M3)

Abstract
A 46-yr-old woman was diagnosed as having M3 variant leukemia in FAB subclassification with disseminated intravascular coagulation (DIC) and the 15;17 translocation. Immunologic examinations revealed that the blast cells exhibited monocytic (Ia+, Mol+, Mo2+, My4+, My7+ and My9+) and T-lymphocytic (OKT11+, Leu4+ and Leu5b+) immunophenotype, with probably a biphenotypic population of cells. Expression of monocytic phenotype on the blast cells suggests that M3 variant includes a subtype with monocytic characteristics, and may be related to the morphologic monocyte-like feature of that of M3 variant.