Acute megakaryocytic leukemia. Description of a case initially seen as preleukemia syndrome

A 52-year-old man had aregenerative anemia unresponsive to pyridoxine hydrochloride. Acute leukemia developed, and he died four months after diagnosis. At autopsy he had acute megakaryocytic leukemia with involvement of bone marrow, liver, spleen, adrenals, kidneys, and thyroid. Chromosomal analysis revealed absence of both diploid and Ph1 chromosomes. A mode of 45 chromosomes and aneuploidy were present. This is similar to the only other case with chromosomal studies. Of the 15 acceptable documented cases, eight were men and seven were women. Their age varied from 28 to 76 (mean, 55) years. Only two were less than 40 years of age. Most had pancytopenia, and all were dead within six months of diagnosis.