Peripheral blood smear from a patient with acute monoblastic leukemia (FAB classification M5). (Wright-Giemsa stain.) The 2 monoblasts on the left have abundant cytoplasm with numerous azurophilic granules. The nuclear membrane of the promonocyte on the right has delicate folds and creases.
From: Brunning RD, McKenna RW. Tumors of the bone marrow. Atlas of tumor pathology (electronic fascicle), Third series, fascicle 9, 1994, Washington, DC. Armed Forces Institute of Pathology.