Peripheral smear from a patient with the typical hypergranular type of acute promyelocytic leukemia (APL)

The white cell count in this type of APL is usually low, with only a few circulating malignant promyelocytes. The abnormal promyelocytes frequently have bi-lobed or dumbbell-shaped nuclei with granular cytoplasm. They can be difficult to recognize due to their scarcity, but when seen, they should immediately raise the possibility of APL.