Succinate Dehydrogenase A-Deficient Renal Cell Carcinoma with Predominantly Papillary Structures: A Case Report and...

Succinate dehydrogenase (SDH)-deficient renal cell carcinoma (RCC) is a rare molecularly defined renal tumor characterized by defects in the subunit types SDHA, SDHB, SDHC, and SDHD, with most of these genetic alterations involving the SDHB subunit, whereas the SDHA, SDHC, and SDHD gene mutations are less frequent. The classic pathological features of SDH-deficient RCC include a nest-like arrangement of tumor cells containing abundant eosinophilic cytoplasm, intracytoplasmic translucent or pale inclusion bodies, and inconspicuous nucleoli. Immunohistochemistry studies have revealed SDH protein deletion with mutations in the SDH gene in this condition. This report presents a 37-year-old female patient diagnosed with SDHA-deficient RCC with a unique pathological morphology characterized mainly by papillary structures mixed with a small number of glandular tubular structures. This was finally confirmed through DNA sequencing. This tumor can be easily confused with other papillary RCCs. The patient underwent chemotherapy and targeted therapy after surgery but unfortunately died eventually. The extremely poor prognosis of the patient suggested that this group of patients should be focused on to improve the treatment and prolong their life span. Owing to the limited existing knowledge of this particular pathological type of RCC, this report would be beneficial as it provides novel insights for the diagnosis and treatment of patients with this type of tumor.