[The role of cytogenetic tests in the diagnosis of malignant hematologic diseases].

In malignant hematological diseases, clonal genetic alterations, such as chromosomal aberrations and gene mutations, are responsible for the uncontrolled division of abnormal hemopoietic cells. The detection of clonal variants has not only diagnostic, but also prognostic and therapeutic significance. They enable risk-based differentiated treatment of patients and the use of targeted (genotype-specific) therapies. Chromosomal abnormalities can be identified with cytogenomic testing (karyotyping, fluorescent in situ hybridization - FISH, microarray). In chronic myeloid leukemia, myelodysplastic neoplasia and acute leukemias, chromosome analysis is a mandatory test at the time of diagnosis. In some lymphoid malignancies (chronic lymphocytic leukemia, multiple myeloma), instead of karyotyping, submicroscopic abnormalities and translocations are detected by FISH method. Despite the rapid spread of high-sensitivity new-generation sequencing techniques, cytogenetic studies are still essential in the routine diagnosis of malignant hematological diseases.