Bone marrow aspirate from a patient with acute promyelocytic leukemia

Bone marrow aspirate from a patient with acute promyelocytic leukemia (APL; formerly described in the French-American-British [FAB] classification as the M3 variant of acute myeloid leukemia). The cytoplasm of these promyelocytes contains densely packed bright pink, reddish-blue, or dark purple granules. Note the cell on the bottom left with a single Auer rod. (Wright-Giemsa stain.)