Phenotyping of acute myelomonocytic (AMMOL) and monocytic leukemia (AMOL): association of T-cell-related antigens and skin-infiltration in AMOL.

Leukemic blast cells in 25 cases of AMMOL (13 cases) and AMOL (12 cases) were positive for My7 (CD13) and My4 (CD14), while only 44% reacted with LeuM3 (another CD14 MoAb). T-cell-related antigens were detected in 44% of the cases (CD2, 24%; CD4, 12%; CD7 36%). The expression of LeuM3 and TcrAg on blast and monocytic cells was mutually exclusive, with three cases expressing neither LeuM3 nor TcrAg. All six patients with myeloperoxidase negative AMOL and the TcrAG+/LeuM3- phenotype had leukemic skin infiltrations.