Incidental Succinate Dehydrogenase (SDH) Deficient Renal Cell Carcinoma and Paraganglioma in a 24-Year-Old

Abstract Introduction/Objective Succinate dehydrogenase (SDH)-deficient renal cell carcinoma (RCC) is rare neoplasm (<0.2% of all RCCs) caused by SDH-subunit gene mutation, usually SDHB. Patients carrying such mutations are also predisposed to other SDH-deficient neoplasms as paraganglioma, gastrointestinal stromal tumor, and pituitary adenoma. Here, we report a case incidental RCC paraganglioma. Methods/Case Report A 24-year-old male without past medical or family history presented ED for perianal abscess. Imaging showed 8-cm heterogeneous left mass (figure-A) 3.3-cm below aortic bifurcation, highly concerning with metastasis. Biopsy kidney nested trabecular epithelial weakly eosinophilic occasionally vacuolated cytoplasm (figure-B). Nuclei were round smooth contour inconspicuous nucleoli. Tumor was immunopositive PAX8, e-cadherin, P504S, CD10, while negative CK7, CD117, Melan-A. SDHB immunostain in tumor intact staining intervening endothelium. Findings consistent RCC. pelvic low-grade that synaptophysin, chromogranin, GATA3, S100-positive sustentacular cells, Patient underwent radical nephrectomy which revealed 7.5-cm, well-circumscribed, tan-red, predominantly solid few cysts. Histologically, had thin fibrous capsule morphologically similar biopsy. limited necrosis, sarcomatoid/rhabdoid differentiation, vascular invasion. Results (if Case Study enter NA) NA. Conclusion entity risk metastasis development neoplasms, requires continued follow-up potential genetic testing patient members. Therefore, including differential diagnosis essential.