SDH (succinate dehydrogenase)- deficient renal cancer is a rare renal cancer (RCC) subtype recently accepted by WHO as an unique RCC subtype with only 59 cases described worldwide. Here we report a case of 17-year old man. The detailed evaluation indicated occurrence of the SDHB-deficient RCC. The genetic testing revealed no germline mutation in SDH genes. Immunohistochemistry showed SDHB deficiency, overexpression of PKM2 and dramatic downregulation of FBP1 metabolic enzymes, unaltered levels of pAMPK and mTOR. Furthermore, the strong upregulation of INI1, BRG1 and overexpression of BAF180 subunits of SWI/SNF ATP-dependent chromatin remodeling complex were found. The identified tumor pathologically did not resemble ccRCC (clear cell renal cell carcinoma) but some metabolic alterations are common for both cancer types. Thus, we postulate that the phenotypical differences between ccRCC and SDHB-deficient RCC may be related to distinct molecular and metabolic alterations. IMPLICATIONS FOR PRACTICE: SDH-deficient RCC is a rare renal tumor occurring also in young age. So far in all described and genetically tested cases the mutations/deletions in SDH genes were found [2]. Here we describe SDHB-deficient RCC without any germ line mutations in SDH genes. Therefore, the genetic analysis for germ line mutations in SDH genes in SDH-deficient RCC, especially in young individuals should be strongly recommended, although up to date is not obligatory. This knowledge will allow to improve the further patient monitoring including both disease recurrence and new cancer appearance.
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