A case of uncommon metastasis located posterior to the seminal vesicles in renal cell carcinoma.

Renal cell carcinoma (RCC) is known for its potential to metastasize to various sites but metastasis to the area posterior to the seminal vesicles is exceedingly rare. We present the case of a 44 year-old male patient with a history of clear cell RCC (ccRCC) who was found to have suspected metastases to the region posterior to the seminal vesicles and the greater omentum during follow-up after radical nephrectomy. The patient was classified as having a favorable risk according to the International Metastatic RCC Database Consortium criteria. Due to the rarity of this metastasis site, a treatment strategy combining immune-oncology therapy and tyrosine kinase inhibitors (IO-TKI) was initiated. This treatment led to significant reduction of the metastatic lesions, allowing for their complete removal via laparoscopic surgery. Pathologic examination confirmed that the metastatic lesions were consistent with primary ccRCC. No clinical progression was observed 2 months postoperatively. This case highlights the rare occurrence of ccRCC metastasizing posterior to the seminal vesicles and demonstrates the potential effectiveness of combined IO-TKI therapy followed by surgical resection in treating such atypical metastases.