Modern diagnostics in acute leukemias.

Acute leukemias are a heterogeneous group of diseases. The different subtypes are characterized by certain clinical features and specific laboratory findings. Large clinical trials have confirmed the important impact of the underlying biology of each subtype for clinical outcome. Improvements in patient's treatment resulting in better survival rates are closely linked to the biological understanding of the disease subtypes, which is assessed by specific diagnostic approaches. Thus, several diagnostic techniques are mandatory at diagnosis for classification and for individual therapeutic decisions. Furthermore they are also needed for follow up studies focusing especially on minimal residual disease (MRD) to guide further treatment decisions based on the response of the disease to given treatment protocols. Only by using a comprehensive diagnostic panel including cytomorphology, cytochemistry, multiparameter flow cytometry (MFC), cytogenetics, fluorescence in situ hybridization (FISH) and molecular genetic methods the correct diagnosis in acute leukemias can be established today. The results serve as a mandatory prerequisite for individual treatment strategies and for the evaluation of treatment response using especially newly defined and highly specific MRD markers.