Increased blasts mimicking acute leukemia in a patient with polysubstance abuse.

Toxic insult to the bone marrow may result in partial or complete suppression, with or without reactive changes, and probable eventual regeneration of hematopoietic elements. During the regenerative process, increased blasts may be observed. Distinguishing these changes from an acute leukemic process can be difficult. In particular, the diagnosis of hypocellular bone marrow with increased blasts, also known as hypocellular or hypoplastic acute leukemia, presents a diagnostic dilemma for pathologists. We report a case of hypocellular marrow with increased blasts in a 50-year-old man with an extensive history of alcohol and drug abuse in whom chemotherapy was deferred. Recovery of peripheral blood cell counts and reticulocytosis occurred with withdrawal of the offending agents, and he remains alive and well 1 year later.