A Case of Synchronous Bilateral Spermatocytic Tumor.

Introduction: Spermatocytic tumor is rare, accounting for approximately 1% of all testicular neoplasms. It is clinically and pathologically distinct from classical seminoma and typically presents as a unilateral, slow-growing mass in older men. Case Presentation: A 54-year-old man presented with painless bilateral scrotal swelling. Imaging revealed heterogeneous masses in both testes, and laboratory findings were within normal limits. Left high orchiectomy revealed polygonal cells with clear cytoplasm, initially suggesting seminoma. Given the patient's age and histological features, immunohistochemistry was performed. A right high orchiectomy was subsequently conducted. Both tumors were diagnosed as spermatocytic tumors based on SALL4 positivity and PLAP, c-kit, and Vimentin negativity. The patient developed postoperative hypogonadism and began testosterone replacement therapy. No recurrence was observed during 1-year follow-up. Conclusion: This rare case of synchronous bilateral spermatocytic tumor highlights the importance of considering this diagnosis in older men with bilateral testicular masses. Immunohistochemistry is essential for accurate identification.