ABSTRACT
Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) with characteristic biologic and clinical features that are highly curable. The APL variant is characterized by atypical promyelocytes with marked nuclear irregularities, mostly in the form of bilobation, folding, or convolution. Additional genetic abnormalities including trisomy 8 and complex karyotypic changes can occur in APL. Hypergranular APL needs to be differentiated from AML composed of blasts with numerous cytoplasmic granules and/or Auer rods. Because of the tendency for disseminated coagulopathy, a typical and life-threatening complication of APL, establishing the correct diagnosis of APL in a timely fashion, is critical in management of patients with APL. The bone marrow often shows an increased number of small hypolobated megakaryocytes and multilineage dysplasia. There are no specific immunophenotypic findings, as blasts may display myeloid, megakaryocytic, or monocytic differentiation. Patients are often refractory to conventional therapy and have short overall survival.
