MICM characteristics and typing diagnosis in acute myelogenous leukemia patients (AML-M2) with complex karyotype t (2;21;8)(p12;q22;q22) / 中国实验血液学杂志

ABSTRACT

This study was purposed to investigate the acute myeloid leukemia with complex karyotype t(2;21;8)(p12;q22;q22) (AML-M(2)) by using morphologic, immunologic, cytogenetic and molecular biologic classification technique (MICM) and to analyze the MICM characteristics of AML-M(2) and their diagnostic significance. The FAB typing of bone marrow cells (BMCs) was performed by Wright-Giemsa staining and histochemical staining of BM smears; the immunophenotype of leukemic cells was detected by flow cytometry; the karyotypes of chromosome samples prepared by short-term (48 hours) conventional culture of fresh BMCs were analyzed by RHG banding technique; the FISH signaling in mitotic metaphase was determined by dual color and dual fusion AML/ETO probe and chromosome painting probe, and was compared with results of conventional cytogenetic assay; the AML/ETO fusion transcripts were detected by nested RT-PCR. The results indicated that the bone marrow smears of case 1 showed extremely hyperplasia with myeloblasts in which a ratio of eosinophilic granulocytes and monocytes increased. Case 2 accorded with AML-M(2b) in which abnormal increase of myelocytes mainly appeared. The complex karyotype t(2;21;8)(p12;q22;q22) was detected by cytogenetic analysis combined with FISH in both two cases and AML1/ETO fusion transcripts were found by RT-PCR as well. The immunophenotype assay showed high co-expression of CD34 and HLA-DR accompanied with CD19 and CD56 expressions. It is concluded that application of MICM has an important significance for correct diagnostic typing of AML-M2 with complex karyotype variant of t(8; 21)(p12;q22;q22).