Acute myeloid leukemia (AML FAB M0)

Bone marrow aspirate from a patient with AML (FAB classification M0). (Wright-Giemsa stain). The blasts lack differentiating features and were nonreactive to Sudan Black B and myeloperoxidase staining. More than 20% of the blasts expressed myeloid antigens CD13 and CD33. The blasts were terminal transferase negative and nonreactive with antibodies to lymphocytes. Auer rods were not found.