Xp11.2易位/TFE3基因融合相关性肾癌的病理特征与临床分析

目的探讨Xp11．2易位／TFE3基因融合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11例Xp11．2易位／TFE3基因融合相关性肾癌进行光镜观察和免疫组织化学研究及随访10～112个月,并复习相关文献。结果11例肿瘤中女性7例,男性4例。年龄8～26岁,平均16、3岁。肿块直径2．5～6．0cm。光镜下癌组织呈两种结构,一种为腺管状、乳头状、巢状分布。细胞界限清楚,有大量透明或嗜酸性胞质。泡状染色质、核仁明显,沙砾体多见。另一种结构更加紧密,多见实性巢状结构,癌细胞缺乏大量的胞质,核仁不明显,沙砾体少见。免疫表型：本组11例均TFE3、CD10、a-甲酰基-CoA消旋酶（P504s）弥漫表达,细胞广谱角蛋白（CK—pan）、上皮细胞膜抗原（EMA）、波形蛋白仅部分病例表达,所有病例CK7、肾脏特异性钙黏蛋白（Ksp—cadherin）、CD117阴性表达。结论Xp11．2易位／TFE3基因融合相关性肾癌是一种少见肿瘤,诊断主要依据患者的年龄。病理学形态和免疫组织化学TFE3阳性。

Renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions: a study of 11 cases and review of literature

OBJECTIVE: To study the clinicopathologic features, differential diagnosis and prognosis of renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions. METHODS: The histopathologic findings and immunophenotype of 11 cases of renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions were studied. Follow-up data (ranged from 10 to 112 months) were also analyzed. RESULTS: There were a total of 7 females and 4 males. The age of patients ranged from 8 to 26 years (mean = 16.3 years). The diameter of the tumors varied from 2.5 to 6.0 cm. Histologically, two morphologic patterns were seen. The first pattern consisted of alveolar, papillary or nested architecture. The tumor cells contained voluminous, clear to eosinophilic cytoplasm, distinct cell borders, vesicular chromatin, and prominent nucleoli. Psammoma bodies were frequently found and could be abundant. In contrast, the second pattern was composed of nested and compact architecture. The tumor cells possessed less abundant cytoplasm and inconspicuous nucleoli. Few psammoma bodies were detected. Immunohistochemical study showed that all cases strongly expressed TFE3, CD10 and P504s. Variable positivity for pan-cytokeratin, epithelial membrane antigen and vimentin was also noted. None of them expressed CK7, Ksp-cadherin and CD117. CONCLUSIONS: Renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions is a newly described but rarely encountered subtype of renal cell carcinoma. Pathologic diagnosis can be established when taken age of the patients, histopathologic findings and immunoreactivity for TFE3 protein into consideration.