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Re‐evaluation of 33 ‘unclassified’ eosinophilic renal cell carcinomas in young patients
Author(s) -
Li Yunjie,
Reuter Victor E,
Matoso Andres,
Netto George J,
Epstein Jonathan I,
Argani Pedram
Publication year - 2018
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.13395
Subject(s) - sdhb , eosinophilic , renal cell carcinoma , pathology , medicine , immunohistochemistry , oncocytoma , clear cell , biology , mutation , biochemistry , germline mutation , gene
Aims We sought to determine if some unclassified renal cell carcinomas ( RCC s) in children and young adults that are characterised by predominantly eosinophilic cytoplasm are related to the recently described succinate dehydrogenase ( SDH )‐deficient RCC , fumarate hydratase ( FH )‐deficient RCC or eosinophilic solid and cystic ( ESC ) RCC . Methods and results We reviewed 33 unclassified RCC s with predominantly eosinophilic cytoplasm in patients aged 35 years or younger. Immunohistochemistry ( IHC ) for SDHB , FH and CK 20 (a marker of ESC ) was performed in all cases. IHC for 2‐succinocysteine (2 SC ) was performed on RCC with loss of FH labelling. Four RCC (12%) (median age 18 years) demonstrated loss of FH labelling as well as aberrant 2 SC labelling, and were thus classified as FH ‐deficient RCC s. Importantly, none of these cases demonstrated the characteristic macronucleoli typical of FH ‐deficient RCC . Eight RCC (24%) (median age 20.5 years) demonstrated loss of SDHB and were reclassified as SDH ‐deficient RCC s. Importantly, only four of eight SDH ‐deficient RCC demonstrated the characteristic cytoplasmic vacuoles and inclusions of typical SDH ‐deficient RCC . Ten RCC (30%) (median age 27 years) were reclassified as ESC RCC s. Four of 10 ESC RCC were multifocal (one bilateral), four of 10 ESC RCC occurred in males and one patient presented with liver and lung metastases, all not described previously in ESC . Eleven RCC (33%) remained unclassified. Conclusions Pathologists should have a low threshold for performing FH , SDHB and CK 20 IHC when confronted with unclassified eosinophilic RCC or ‘oncocytoma’ in young patients.