[Transient myeloproliferative syndrome or congenital leukemia in a newborn infant with Down syndrome?]. / Przejsciowy zespól mieloproliferacyjny czy bialaczka wrodzona u noworodka z zespolem Downa?

A newborn with Down syndrome (karyotype 47 xy + 21) was observed in whom a transient myeloproliferative reaction occurred, perhaps connected with perinatal infection. The reaction regressed spontaneously. However, the possibility of complete remission cannot be excluded since the proliferative changes may be a preliminary stage of leukaemia.