[Current aspects of the laboratory diagnosis of acute leukemia in children]

A review is given of recent developments in diagnosing leukemia. Acute megakaryoblastic leukemia has been in the past an unclassifiable leukemia, but with electronmicroscopy it has become classifiable. The recent description in the literature of myelodysplastic syndrome (pre-leukemia) has lead to earlier diagnosis. Immunephenotyping of early T-cel leukemia is now possible by showing a T-cel marker positivity present in the cytoplasm. Cytogenetics and molecular cytogenetics appear to become important. In the near future it will be shown whether these new methods, in combination with existing methods can help us determine existing heterogeneity at diagnosis or during the disease.