Acute promyelocytic leukemia in childhood. Report of a case with a review of the literature.

A rare case of acute promyelcytic leukemia (APL) is reported in a 7-year-old boy. The patient displayed the typical features of APL including impaction of the marrow with promyelocytes, marked elevation of the serum vitamin B12 and transcobalamin I levels and a hemorrhagic diathesis. The bleeding diathesis in the case was due to thrombocytopenia, and there was no evidence for disseminated intravascular coagulation.