Synchronous Ovarian Sertoli–Leydig Cell and Clear Cell Papillary Renal Cell Tumors: A Rare Case Without Mutations in Cancer-Associated Genes

(1) Background: Sertoli–Leydig cell tumors (SLCTs) are rare ovarian neoplasms that account for less than 0.5% of all ovarian tumors. They usually affect young women and often present with androgenic symptoms. We report a unique case of a 40-year-old woman diagnosed with both SLCT and clear cell papillary renal cell carcinoma (CCP-RCC), a rare tumor association with unclear pathogenesis. (2) Methods: Both tumors were treated surgically. The diagnostic workup included hormonal testing, imaging studies, and extensive genetic testing, including DICER1 mutation analysis and multiplex ligation-dependent probe amplification (MLPA), as well as the examination of a next-generation sequencing (NGS) panel covering ~280 cancer-related genes. (3) Results: Histopathologic examination confirmed a well-differentiated SLCT and CCP-RCC. No pathogenic variants in DICER1 were identified by WES or MLPA. No clinically relevant changes were found in the extended NGS panel either, so a known hereditary predisposition could be ruled out. The synchronous occurrence of both tumors without genomic alterations could indicate a sporadic event or as yet unidentified mechanisms. (4) Conclusions: This case highlights the importance of a multidisciplinary approach in the management of rare tumor compounds. The exclusion of DICER1 mutations and the absence of genetic findings adds new evidence to the limited literature and underscores the importance of long-term surveillance and further research into potential shared oncogenic pathways.