目的　探讨染色体G显带、荧光原位杂交和流式细胞术在急性粒单核细胞白血病临床诊断、鉴别诊断和预后中的意义。方法　运用染色体G显带和流式细胞术 ,对 15例骨髓细胞形态学拟诊为急性髓系白血病M4型 (AML M4 )的患者进行核型分析和免疫分型 ,并用间期荧光原位杂交技术 (inter phasalfluorescenceinsituhybridization ,I FISH)对其中 6例患者进行检测。结果　染色体G显带核型分析显示正常核型 6例 ,伴有inv(16 ) (p13;q2 2 )异常 2例 ,伴有del(16 ) (q2 2 )、 X ,5 q ,t(8;2 1) (q2 2 ;q2 2 )、t(9 ;2 2 ) (q34;q11)、t(11;17)和t(11;?)异常各 1例 ,另有 2例无分裂相可供分析。I FISH对 3例患者进行CBFβ基因重排检测 ,2例阳性 ,1例阴性 ;对这例阴性患者进一步检测AML1/ETO融合基因 ,结果阳性 ;3例患者检测了MLL基因重排 ,2例阳性 ,1例阴性但伴有t(9;2 2 )异常 ,BCR/ABL融合基因阳性。免疫分型提示 14例患者有髓系和单核系分化抗原的共同表达 ,1例仅有髓系表达。结论　联合运用染色体G显带、荧光原位杂交技术和流式细胞术 ,对于急性粒单核细胞白血病诊断、鉴别诊断和预后 ,具有重要的临床意义 Objective To investigate the significance of chromosome G banding, fluorescence in situ hybridization and flow cytometry in the clinical diagnosis, differential diagnosis and prognosis of acute myelomonocytic leukemia. Methods K - banding and flow cytometry were used to analyze the karyotype and immunophenotype of 15 patients with acute myeloid leukemia M4 (AML M4) type. Six patients were examined by interphase fluorescence in situ hybridization (I FISH). Results The karyotype analysis of chromosome G showed 6 cases of normal karyotype with 2 cases of inv (16) (p13; q2 2) abnormalities accompanied by del (16) (q2 2), X, 5 q, t 1 (q2 2; q2 2), t (9; 2 2) (q34; q11), t (11; 17) and t Available for analysis. I FISH 3 patients with CBFβ gene rearrangement test, 2 patients were positive, 1 negative; further negative detection of AML1 / ETO fusion gene in this negative patients, the result was positive; 3 patients detected MLL gene rearrangement, 2 patients were positive , One negative but associated with t (9; 2 2) abnormalities, BCR / ABL fusion gene positive. Immunophenotyping prompted the co-expression of myeloid and monocytic differentiated antigens in 14 patients and myeloid expression in only one patient. Conclusion The combined use of G-banding, fluorescence in situ hybridization and flow cytometry has important clinical significance for the diagnosis, differential diagnosis and prognosis of acute myelomonocytic leukemia