Objective: To study the clinicopathologic features and immunophenotype of renal cell carcinomas, and to discuss their diagnostic value.
Methods: The clinicopathologic features of 114 cases of renal cell carcinoma were reviewed and categorized on the basis of 2004 WHO classification. Immunohistochemical study for a panel of antibodies (including CK, CD10, vimentin, CD117, AMACR, CK7 and TFE3) was carried out. The follow-up data, if available, were also analyzed.
Results: The cases were reclassified into 5 subtypes, including 77 cases (67.5%) of clear cell carcinoma (CCRCC), 11 cases (9.6%) of papillary renal cell carcinoma (PRCC), 14 cases (12.3%) of chromophobe renal cell carcinoma (chrRCC), 10 cases (8.8%) of renal carcinoma associated with Xp11.2 translocations/TFE3 gene fusions (Xp11.2RCC) and 2 cases (1.8%) of unclassified renal cell carcinoma (unRCC). Immunohistochemical study showed that the expression rates of CK, CD10 and vimentin in CCRCC were 93.5% (72/77), 93.5% (72/77) and 75.3% (58/77), respectively. On the other hand, all the 11 cases of PRCC studied were positive for AMACR. The expression rate of CD117 in chrRCC was 78.5% (11/14). In the 10 cases of Xp11.2 RCC studied, the expression rates of TFE3, AMACR, CD10 and CK were 100% (10/10), 100% (10/10), 90% (9/10) and 70% (7/10), respectively.
Conclusions: The various subtypes of renal cell carcinomas are heterogeneous in histologic appearance and demonstrate distinctive immunophenotype. The expressions of CD10, vimentin, CD117, AMACR, CK7 and TFE3 are helpful in the differential diagnosis.