Cytogenetic analyses (karyotype and, if necessary, appropriate complementary FISH analyses) are mandatory at diagnosis in acute lymphoblastic leukemia (ALL) as their results are taken into account in therapeutic protocols due to their diagnostic and prognostic values. In some cases, karyotype can be completed by other techniques (RT-PCR, RQ-PCR, DNA content, SNP-array, MLPA…) that can be equally or more informative than FISH. Here, we have tempted to establish guidelines concerning karyotype and FISH analyses according to the most recent data of the litterature which is reviewed here, completing the 2008 WHO classification with the recent new cytogenomic entities such as Ph-like ALL and indicating possible therapeutic implications.
Keywords: acute lymphoblastic leukemia; cytogenetics; diagnosis; in situ hybridization (FISH); karyotype.