[Leukemia in pediatric age]

The prognosis for children with leukemia has improved dramatically in the last 20 years based on prospective clinical investigations of best choice and scheduling of combinations of several agents, considering the risk factors of each patient. The authors review childhood leukemia with respect to epidemiology, classification, laboratory findings (including studies of morphology, cytochemistry, immunologic surface markers, biochemical cytoplasmic markers, cytogenetics with the most frequent chromosome anomalies, molecular biology, immunoglobulin gene and T cell receptor gene rearrangements), clinical manifestations, differential diagnosis, prognostic factors treatment. In respect of patients, it is actually followed the concept of a "total therapy", which includes the purpose the eradicate the invading leukemic cells preserving the expression of normal progenitors, and the psychological and social aspects. The authors consider the clinical trials, the role of bone marrow transplantation (BMT), the supportive care, the evaluation of the minimal residual disease, the study of sequelae and late effects in the survivors, the ethical aspects.