摘要目的 探讨t (6; 11)(p21.2; q13)/MALAT1-TFEB基因易位相关性肾癌的临床病理特征、免疫表型、鉴别诊断及预后.方法 对9例TFEB基因易位相关性肾癌进行光镜观察、免疫组织化学EnVision法、荧光原位杂交、MALAT1-TFEB融合基因扩增研究及随访,并复习相关文献.结果 9例肿瘤中女性4例,男性5例.患者年龄21～42岁,平均31.3岁,平均随访31个月,均无病生存.镜下观察4例具特征性“假菊形团”结构,其余5例形态不典型,分别与血管周上皮样细胞肿瘤、肾透明细胞癌、嫌色细胞癌、乳头状肾细胞癌形态学有交叉.肿瘤内时常可见到基底膜样物质,色素及沙砾体.9例TFEB均呈弥漫细胞核表达,E-cadherin、波形蛋白一致强阳性,Ksp-cadherin、CD117阳性比例分别为7/9和6/9,色素性标志物Cathepsin K、HMB45和Melan A的阳性比例分别为8/9、6/9和6/9,广谱细胞角蛋白仅在1例中阳性,TFE3、CD10和CK7均阴性.荧光原位杂交9例均存在异常TFEB分离信号及MALAT1-TFEB融合信号.2例扩增出MALAT1-TFEB融合基因.结论 TFEB基因易位相关性肾癌是一种罕见肿瘤,好发于青壮年,预后较好.诊断可依据患者的年龄、病理学形态和免疫表型,荧光原位杂交检测TFEB基因易位是诊断该肿瘤的金标准.

abstractsObjective To study the clinicopathologic features,immunophenotype,differential diagnosis and prognosis of renal cell carcinoma (RCC) associated with t (6 ; 11) (p21.2 ; q13)/MALAT1-TFEB gene fusion.Methods A total of 9 cases of such rare tumor were selected for clinicopathologic,immunohistochemical and molecular analysis,with review of literature.Results The age of the patients ranged from 21 to 42 years (mean =31.3 years).The patients included four men and five women.Histologically,4 of the 9 cases studied showed classic morphologic features of TFEB RCC,with hyaline material,pigments and psammoma bodies frequently identified.The remaining 5 cases demonstrated uncommon morphology,mimicking perivascular epithelioid cell neoplasm,clear cell RCC,chromophobe RCC or papillary RCC.Immunohistochemical study showed that TFEB and vimentin were positive in all cases.Most of the tumors studied also expressed Ksp-cadherin,E-cadherin,CD117,HMB45,Melan A and Cathepsin K.CKpan showed immunostaining in only 1 case.The staining for TFE3,CD10 and CK7 were all negative.TFEB gene rearrangement was detected in all the 9 cases studied using fluorescence in-situ hybridization.MALAT1-TFEB fusion gene was identified in 2 cases by polymerase chain reaction and direct sequencing.TFEB RCC seemed to be an indolent tumor.During a mean follow-up of 31 months,none developed tumor recurrence,progression,or metastasis.Conclusions TFEB fusion-associated RCC is a rare neoplasm,tends to occur in young age group and carries an indolent behavior.Diagnosis relies on clinicopathologic findings and immunohistochemical analysis.TFEB break-apart FISH assay is a reliable tool in confirming the diagnosis.