Acute myelomonocytic leukemia (M4)

Bone marrow smear from a patient with acute myelomonocytic leukemia (FAB classification M4). (Wright-Giemsa stain). The 2 promyelocytes on the left (arrows) with basophilic cytoplasm containing coarse azurophilic granules contrast with the 2 promonocytes on the right (dashed arrows) which have abundant pale cytoplasm and delicate nuclear folds.