t(6;11)(p12;q21)/TFEB基因融合相关性肾细胞癌的临床病理学观察

Clinicopathological features of t(6;11)(p12;q21)/TFEB renal cell carcinoma

目的 探讨t(6;11)(p12;q21)/TFEB基因融合相关性肾细胞癌(renal cell carcinoma, RCC)的临床病理学特点、免疫表型、诊断和鉴别诊断,提高对该肿瘤的认识。方法 对1例t(6;11)(p12;q21)/TFEB基因融合相关性RCC进行临床病理学、免疫组织化学、和遗传学分析,并复习相关文献。结果 患者女性,20岁,CT扫描发现右肾下极肿物,直径2.5 cm,界限清。大体检查,肿物大小2.5 cm×2.0 cm×2.0 cm,界限清。镜下观察,肿瘤内可见大、小2种肿瘤细胞。大细胞胞质透亮至淡红染,细胞界限清楚。小细胞界限不清,胞质红染,围绕透明基质排列成菊形团样结构。肿瘤细胞表达弥漫表达CK(广谱)、EMA、TFEB和Melan-A。FISH检测显示该肿瘤TFEB基因断裂阳性。结论 t(6;11)(p12;q21)/TFEB基因融合相关性RCC极为罕见,预后较好,确诊需结合临床病理学特征、免疫表型和FISH检测。

Objective To study the clinicopathologic features, immunophenotype, diagnosis and differential diagnosis of t(6;11)(p12;q21)/TFEB renal cell carcinoma(RCC) so as to improve the recognition of this lesion. Methods A case of t(6;11)(p12;q21)/TFEB RCC was investigated for clinicopathological, immunohistochemical, and genetic characteristics, and the relevant literature was reviewed as well. Results A 20-year-old female was found a well-defined mass measuring 2.5 cm in the lower pole of the right kidney by CT scan. On macroscopic examination, the circumscribed tumor was 2.5 cm×2 cm×2 cm in size and firm in texture and the cut surface was tan and yellow in color. Histologically, the tumor was composed of two populations of cells: large and small cells. The larger cells was well-defined with clear to faintly eosinophilic cytoplasm. The ill-defined smaller cells had eosinophilic and were arranged around the hyaline substrate forming the rossete-like structures. Immunohistochemically, the tumor cells were diffusively positive for CKpan, EMA, TFEB and Melan-A. FISH assay demonstrated the TFEB break-apart. Conclusiont(6;11)(p12;q21)/TFEB RCC is an exceedingly rare lesion with an indolent clinical course and its correct diagnosis is based on the combination of clinicopathologic features, immunophenotype and FISH assay.