Acute myeloid leukemia developed in two men with well-documented agnogenic myeloid metaplasia 49 and 27 months, respectively, after initial diagnosis. Both men had spontaneous hematologic remissions of myeloid metaplasia 22 and 16 months prior to leukemic transformation. Neither patient received any precedent radiation or cytotoxic chemotherapy. The remissions and subsequent transformation to acute leukemia were documented by bone marrow aspiration, biopsy, and reticuloendothelial marrow scans, as well as in vitro cell cultures and cytogenetic study. A review of the literature revealed nine other patients who had conversion to acute leukemia in the absence of preceding radiation or cytotoxic chemotherapy. However, the present report seems to be the first describing spontaneous hematologic remission prior to transformation to leukemia.
(Arch Intern Med 1981;141:1481-1484)