1. Approach for reclassification of collecting duct carcinoma and comparative histopathological analysis with SMARCB1/INI1-deficient renal cell carcinoma and fumarate hydratase-deficient renal cell carcinoma
- Author
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Daisuke Kiyozawa, Kenichi Kohashi, Dai Takamatsu, Takeshi Iwasaki, Daiki Shibata, Takumi Tomonaga, Yuki Tateishi, Masatoshi Eto, Mitsuru Kinjo, Kenichi Nishiyama, Kenichi Taguchi, Yumi Oshiro, Yusuke Kuboyama, Mitsuko Furuya, and Yoshinao Oda
- Subjects
Humans ,SMARCB1 Protein ,Carcinoma, Renal Cell ,Immunohistochemistry ,Kidney Neoplasms ,Pathology and Forensic Medicine ,Fumarate Hydratase ,Retrospective Studies - Abstract
Collecting duct carcinoma (CDC) is a rare subset of high-grade renal cell carcinoma (RCC). To diagnose CDC, it is necessary to rule out other renal tumors including renal medullary carcinoma and fumarate hydratase (FH)-deficient RCC. However, there is overlap in the morphology of these three tumors, which all have poor outcomes. There is also still a need to sufficiently examine the therapeutic strategies for each of these tumors. In this study, we retrospectively reclassified invasive/infiltrating high-grade RCC and investigated its pathological features. We reviewed 18 cases previously diagnosed as "CDC," "FH-deficient RCC," and "unclassified RCC," which were reclassified as SMARCB1/INI1-deficient RCC, FH-deficient RCC, and CDC by SMARCB1/INI1, FH, and 2SC immunohistochemistry (IHC) and FH gene mutational status. As the result, 18 cases were reclassified into 2 cases of SMARCB1/INI1-deficient RCC, 7 cases of FH-deficient RCC, and 9 cases of CDC. The morphological features of each group overlapped, and no specific immunohistochemical expression except for SMARCB1/INI1, FH, and 2SC was detected. These results suggest that invasive/infiltrating high-grade RCC should be diagnosed by the combination of immunohistochemistry and molecular biological technique.
- Published
- 2022