Congenital leukaemia: the Dutch experience and review of the literature

We reviewed Dutch patients and those described in the literature with congenital leukaemia in the past 25 years, with the intention to obtain an overview of the characteristics of this rare disease. Among the 117 patients reviewed, acute myeloid leukaemia (AML) was more frequent (64%) than acute lymphoblastic leukaemia (ALL, 21%). Most patients had a high leukaemic cell load with hepatosplenomegaly, leukaemia cutis and hyperleucocytosis. Cytogenetic abnormalities were found in the majority of the patients tested (72%); 11q23 abnormalities were found in less than half of them (42%). The probability of overall survival at 24 months was only 23%. When congenital AML and ALL were compared, clinical characteristics and overall survival were not significantly different. However, in patients at risk, the probability of event-free survival (EFS) and disease-free survival (DFS) were significantly higher in AML than in ALL, 43% versus 13% and 68% versus 0% respectively. Among the congenital AML cases, six spontaneous remissions have been described. In conclusion, the clinical characteristics of congenital leukaemia differ from those of leukaemia in older children and prognosis is generally poor. Once complete remission is achieved, patients with AML fare better than those with ALL. Chemotherapy for congenital leukaemia needs improvement to increase the sustained remission rate.