t（15；17）急性早幼粒细胞白血病向t（11；17）急性单核细胞白血病转化一例

Transformation from promyelocytic leukemia with t （15; 17 ）（q22; q21 ） to acute monocytic leukemia with t （11~17） （q23;q21）in a case

目的报告1个急性早幼粒细胞白血病（acute promyelocytic leukemia, APL）治疗第13个月向t（11；17）（q23；q21）急性单核细胞白血病转化的病例。方法应用骨髓细胞形态学、免疫分型、细胞遗传学以及实时定量逆转录PCR（real-time quantitative reverse-transcription polymerase chain reaction, RQ-PCR）方法对疾病进行诊断和分型。结果患者起病时骨髓细胞形态学和免疫分型均显示为典型的APL，染色体分析核型为t（15；17）（q22；q21），RQ-PCR示PML-RARα融合基因为S型。该患者治疗第13个月时出现疾病反复，骨髓细胞形态学和免疫分型显示转化为急性单核细胞白血病，染色体核型为t（11；17）（q23；q21），进一步的荧光原位杂交和RQ-PCR证实具有MLL-AF17q融合基因而非PLZF-RARα。结论APL治疗后可以继发治疗相关的急性髓性白血病（therapy-related acute myeloid leukemia, t-AML），t（11；17）（q23；q21）不仅可以出现于变异型APL，还可出现于t-AML，荧光原位杂交和RQ-PCR方法进行融合基因检测是确定诊断的必要手段。

ObjectiveTo report on a case of therapy-related acute monocytic leukemia（t-AML） with t（11; 17）（q23; q21）/MLL-AF17q after successful treatment for acute promyelocytic leukemia（APL） with t（15; 17）（q22; q21）/PML-RARα.MethodsA MICM method （bone marrow morphology（M）, immunophenotype（I）, cytogenetics（C）, and molecular biology（M）） was used for the diagnosis and classification of the disease at the time of onset and transformation.ResultsThe patient was initially identified with typical morphology and immunophenotype of APL. She has carried t（15; 17）（q22; q21） and PML-RARα fusion gene but was without t（11; 17）（q23; q21） or MLL gene abnormalities. After 13 months of successful treatment, she has transformed to AML with typical morphology and immunophenotype. t（11; 17）（q23; q21） and MLL-AF17q fusion gene were detected in her bone marrow sample, while no PLZF-RARα fusion gene was detected by real-time quantitative reverse-transcription PCR（RQ-PCR） and fluorescence in situ hybridization（FISH）. Conclusiont-AML is a serious complication after successful treatment of APL. t（11; 17）（q23; q21） is not specific for the diagnosis of variant APL and can also be detected in t-AML. RQ-PCR and FISH are essential for the diagnosis of such patients.