Primary adenocarcinoma of the spermatic cord: a case report and review of the literature.

Background: Primary malignant neoplasms of the spermatic cord are extremely rare, with most reported cases being sarcomas or metastatic carcinomas. However, primary adenocarcinoma of the spermatic cord has not been previously reported.

Case presentation: A 34-year-old male with a solid mass in the right spermatic cord, was eventually diagnosed with primary adenocarcinoma. Histological examination revealed a moderately-to-poorly differentiated adenocarcinoma exhibiting glandular, cribriform, or nested growth patterns, characterized by medium to large-sized cells and focal extracellular mucus. Immunohistochemical analysis demonstrated positive staining for CK (AE1/AE3), CK8/18, CK19, MOC31 (EP-CAM), and Ber-EP4, while negative staining was observed for CK7, D2-40, WT-1, MC, PAX-8, NKX3.1, PSA, CEA, TTF-1, and NapsinA. Furthermore, a complete loss of INI-1 expression and consistent BRG1 expression were noted in all tumor cells. Next-generation sequencing revealed SMARCB1 deletion, low tumor mutation burden (TMB-L), and microsatellite stability (MSS).

Conclusion: We reported the first case of primary adenocarcinoma of the spermatic cord with SMARCB1 (INI-1) deficiency. This case contributes to the expanding understanding of rare neoplasms and underscores the importance of further research into therapeutic strategies targeting SMARCB1-deficient tumors.