TRANSIENT MYELOPROLIFERATIVE DISORDER AND ACUTE MYELOID-LEUKEMIA - STUDY OF 6 NEONATAL CASES WITH LONG-TERM FOLLOW-UP

Six neonates with hematological and clinical pictures indistinguishabl e from acute myeloid leukemia were studied. Two patients had Down synd rome and three others had either +21 or i(21q) chromosomal abnormaliti es in their blood cells at presentation. Granulocyte-macrophage colony -forming unit assays performed in bone marrow and peripheral blood mon onuclear cells revealed abnormal growth patterns in two patients; both died of progressive disease of acute myeloid leukemia. All the other four neonates with normal in vitro cell growth pattern had spontaneous remission within 7 months. Of these four patients, one remains well a nd in remission for 8 years and the other three developed acute myeloi d leukemia at the ages of 15, 32 and 19 months, respectively. We concl ude that the in vitro cell growth pattern is helpful to distinguish tr ansient myeloproliferative disorder from congenital acute myeloid leuk emia and that patients with the former condition are at risk to develo p acute myeloid leukemia subsequently.