Spontaneous remission in neonates with Down's syndrome and acute myelogenous leukemia - Transient myeloproliferative disease

Transient myeloproliferative disorders (TMD), indistinguishable from acute leukemia by clinical and morphological criteria, have been described in neonates with Down's syndrome. However, spontaneous remission occur with supportive care without any specific chemotherapy. Pathogenesis of this leukemic reaction is unknown. It appears that the additional chromosome 21 is the key for the leukemic reaction. The classification according to the FAB criteria by morphological and immunological parameters predominantly reveals the subtype of acute megakaryoblastic leukemia (FAB M7). The risk of acute myeloid leukemia, especially of the subtype M7, is greatly increased in these children during the first 4 years of life. Future investigations of the hematopoietic disorders in Down's syndrome should include the definition of the cellular, phenotypic and genetic features of TMD and FAB M7 to clarify the pathophysiological correlations between the initial TMD and the occurrence of acute myeloid leukemia in later life. The results of these investigations might be a model for one particular form of spontaneous remission in cancer patients.