IMMUNOPHENOTYPING OF CONGENITAL LEUKEMIA

Congenital leukemia is a rare but well-documented disease in which a l eukemic process is detected at birth or very shortly thereafter, An es timated 175-200 reports of congenital leukemia have appeared in the li terature. The majority of the cases reported have not undergone thorou gh immunophenotyping, but rather have been assigned lineage based on c ytochemical and morphological studies. Historically, a large proportio n of congenital leukemias have been thought to be of the myeloid linea ge, in contrast to pediatric leukemias in general, which are primarily lymphoid. The precise proportions of the lineage assignments may be d istorted by the inclusion of cases of transient myeloproliferative dis orders (TMD) as congenital leukemia. The immunophenotyping data availa ble to date suggest that congenital leukemias are phenotypically heter ogeneous, lacking any common distinguishing markers, The prognosis for congenital leukemias is usually poor if leukemoid reactive processes, such as TMD, are carefully excluded. (C) 1995 Wiley-Liss, Inc.