Acute myeloid leukemia with pseudo-Chèdiak-Higashi anomaly exhibits a specific immunophenotype with CD2 expression.

Acute myeloid leukemia (AML) with pseudo-Chèdiak-Higashi (PCH) anomaly is a rare morphologic entity. We characterized 5 cases by multiparameter flow cytometry and found that in all cases, the blasts aberrantly expressed CD2, a pan-T cell-associated marker, in addition to their myeloid-associated markers. In contrast, CD2 was expressed in only 25 (17.9%) of 140 cases of newly diagnosed AML without PCH anomaly. CD2 expression correlated strongly with AML with PCH anomaly (P < .01), suggesting a link between a specific immunophenotypic marker, CD2, and AML with PCH anomaly.