Atypical acute promyelocytic leukemia (M3 variant): description of two cases.

A variant form of acute promyelocytic leukemia has been recently described, characterized by a particular morphological picture associated with severe disseminated intravascular coagulation, with hyperleukocytosis at onset in most cases, and often a rapidly fatal outcome. Reviewing our case series of the past 3 years, we have identified 2 cases which presented with this typical clinical and hematological picture, in which diagnoses have been made retrospectively. The possibility of diagnosing this variant at onset even only on the basis of cytomorphology is discussed as well as the advisability of studying a new therapeutic approach for cases of this type in a attempt to improve its otherwise very unfavorable prognosis.