Immunoexpression of SDHB, FH, and CK20 among eosinophilic renal tumors: A tissue microarray study

• Published in: Annals of diagnostic pathology 2021-10, Vol.54, p.151788-151788, Article 151788
• Main Authors: Karatay, Huseyin, Ozluk, Yasemin, Dogan, Mehmet Ali, Erdem, Selcuk, Kilicaslan, Isin
• Format: Article
• Language: English
• Subjects: Adult; Cytokeratin 20; Diagnosis, Differential; Eosinophilic renal tumors; Eosinophilic, solid, and cystic renal cell carcinoma; Female; Fumarate hydratase; Fumarate Hydratase - drug effects; Fumarate Hydratase - immunology; Fumarate Hydratase - metabolism; Humans; Immunosuppression Therapy - methods; Keratin-20 - immunology; Keratin-20 - metabolism; Kidney Neoplasms - diagnosis; Kidney Neoplasms - immunology; Kidney Neoplasms - pathology; Male; Middle Aged; Succinate Dehydrogenase - drug effects; Succinate Dehydrogenase - immunology; Succinate Dehydrogenase - metabolism; Succinate dehydrogenase B; Succinate dehydrogenase-deficient renal cell carcinoma
• ISSN: 1092-9134; 1532-8198
• DOI: 10.1016/j.anndiagpath.2021.151788

Differential diagnosis can be a challenge for eosinophilic subtypes of renal cell tumors due to their overlapping histomorphological and immunohistochemical features. We aimed to investigate the frequency of rare variants of renal cell carcinomas (RCCs) such as succinate dehydrogenase-deficient RCC (SDDRCC), hereditary leiomyomatosis and RCC (HLRCC)-associated RCC, and eosinophilic, solid, and cystic RCC (ESCRCC) in our population. Renal tumors which could be considered in the eosinophilic tumor category were included: 91 conventional clear cell RCCs with eosinophilic cytoplasm, 72 papillary RCCs, 74 chromophobe RCCs, 88 oncocytomas, and 37 other rare subtypes. Using the tissue microarray method, succinate dehydrogenase B (SDHB), fumarate hydratase (FH), and cytokeratin 20 (CK20) antibodies were performed by immunohistochemistry. Immunohistochemistry was repeated on whole block sections for selected cases. The utility of these antibodies in the differential diagnosis was also investigated. Loss of SDHB expression was detected in three tumors, two of which showed typical morphology for SDDRCC. In additional two tumors, SDHB showed weak cytoplasmic expression without a mitochondrial pattern (possible-SDHB deficient). None of the tumors showed loss of FH expression. Heterogeneous reactions were observed with SDHB and FH antibodies. Only one ESCRCC was detected with diffuse CK20 positivity. SDDRCCs, HLRCC-associated RCCs, and ESCRCCs are very rare tumors depending on the population. Possible weak staining and focal loss of SDHB and FH expression should be kept in mind and genetic testing must be included for equivocal results. •Eosinophilic renal tumors were evaluated with tissue microarray method.•Succinate dehydrogenase-deficient RCCs diagnosed with loss of SDHB were infrequent.•Eosinophilic, solid, and cystic RCC was extremely rare.•Heterogeneous reactions were observed with SDHB and FH antibodies.