Hydrops fetalis and neonatal leukemia in Down syndrome.

Four newborn infants with Down syndrome and manifestations of neonatal leukemia are described. One of the four was stillborn, two died shortly after birth, and a fourth survived and all evidence of leukemia disappeared in the first month of life. Three of the four cases had hydrops fetalis, and a fourth was a macerated stillborn. Nine other similar reported cases are reviewed. We conclude that neonatal leukemia in Down syndrome is a form of leukemia that is usually transient, with spontaneous recovery, but may be fatal at or around the time of birth with manifestations of hydrops fetalis, hepatosplenomegaly, and/or progressive liver disease.