[Acute leukemia in childhood].

Acute leukemias account for one third of all childhood malignancies. The incidence of acute lymphoblastic leukemias (ALL) is 5 times greater than that of acute non-lymphoblastic leukemias (ANLL). Presenting symptoms of acute leukemias reflect bone marrow failure (anemia, bleeding, infections). Diagnostic procedures are extensive (cytology, cytochemistry, immunophenotyping, cytogenetics, molecular biology). Therapy schedules are adapted in respect to individual risk factors. Two thirds of children with ALL are cured. A general reduction of treatment intensity is not possible. Only the radiotherapy of the CNS could be reduced within the last years. Remission induction failures and relapses are the main problems in the treatment of ANLL. One third of the children with ANLL are cured. Because of their worse prognosis infant leukemias represent a special problem.