TFE3 is accepted as a good marker for the diagnosis of Xp11 translocation renal cell carcinoma. However, the significance of TFE3 in other types of renal cell carcinomas remains unclear. We examined the expression of TFE3 using immunohistochemistry by automated Ventana BenchMark XT system in 1818 consecutive renal cell carcinomas and verified the strong positive cases with TFE3 break-apart fluorescence in situ hybridization and RNA sequencing. Among the 27 renal cell carcinomas with TFE3 strong positive immunostaining, 20 cases were diagnosed as Xp11 translocation renal cell carcinoma, and seven cases were diagnosed as clear cell renal cell carcinoma. We further analyzed the morphology, clinicopathological features, and immunohistochemistry markers (CK7, CD117, CD10, P504s, vimentin, CA-IX, AE1/AE3, EMA, HMB45, Melan-A, and cathepsin K) of them. Pale to eosinophilic flocculent cytoplasm and psammomatous calcification were seen only in Xp11 translocation renal cell carcinomas (P < 0.05). Tumor necrosis occurred in all four cases of Xp11 translocation renal cell carcinomas with pT3a stage, which had local recurrence and distant metastasis (two of them died) within 3 years. The expressions of Vimentin, CA-IX, AE1/AE3, and EMA were significantly different between them (P < 0.05). CA-IX was diffusely strong positive in clear cell renal cell carcinomas but negative or focally mild positive in Xp11 translocation renal cell carcinomas. Our study first demonstrates that a very small minority (0.4%) of clear cell renal cell carcinomas with TFE3 strong positive immunostaining, which points out a potential pitfall in diagnosis of Xp11 translocation renal cell carcinomas by TFE3 immunohistochemistry. CA-IX is a good marker to distinguish clear cell renal cell carcinoma with TFE3 strong positive immunostaining from Xp11 translocation renal cell carcinoma. Tumor necrosis could be a potential factor relevant to pT3a stage, which may be a high-risk factor for the patients with Xp11 translocation renal cell carcinomas.
Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc. 2019 Jun 07 [Epub ahead of print]
Bo Yang, Haoqing Duan, Wenfeng Cao, Yuhong Guo, Yanxue Liu, Lin Sun, Jingyi Zhang, Yan Sun, Yongjie Ma
Department of Pathology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin's Clinical Research Center for Cancer, Tianjin, China., Clinical Laboratory Center, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China., Department of Pathology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin's Clinical Research Center for Cancer, Tianjin, China. ., Department of tumor cell biology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin's Clinical Research Center for Cancer, Tianjin, China. .