ACUTE MEGAKARYOBLASTIC LEUKEMIA FOLLOWING TRANSIENT MYELOPROLIFERATIVE DISORDER IN A PATIENT WITHOUT DOWN-SYNDROME

Transient myeloproliferative disorder (TMD) and subsequent acute myelo id leukemia (AML) occur with increased frequency in infants and childr en with Down syndrome, TMD can also occur in phenotypically normal new borns. We describe the second case of a non-Down syndrome child with T MD who subsequently developed AML. Trisomy 21 karyotype was restricted to hematopoietic cells in the blood and bone marrow, No other karyoty pic abnormalities were found, Leukemic blasts showed megakaryoblastic features with immunophenotyping. This case shows that TMD in a child w ithout Down syndrome may not be entirely benign. Close follow-up is wa rranted. (C) 1994 Wiley-Liss, Inc.