Prostatic Metastasis of Bilateral Metachronous Testicular Cancer: A Case Report and Review of the Literature.

Testicular cancer is an uncommon malignancy that primarily affects young men. Most cases are germ cell tumors (GCTs), which may present as seminomatous or non-seminomatous types. Bilateral occurrence is unusual, often developing at different times. Typical metastatic sites include retroperitoneal lymph nodes, lungs, and mediastinum, whereas prostate involvement is exceptionally uncommon. We report a 39-year-old man with a history of bilateral, metachronous testicular cancer treated initially with orchiectomy and chemotherapy for a right-sided mixed GCT, followed by orchiectomy for a left-sided non-seminomatous germ cell tumor (NSGCT). He presented seven years later with urinary symptoms, elevated tumor markers, and imaging that revealed a large pelvic mass infiltrating the prostate, seminal vesicles, and left ureter. Biopsy confirmed metastatic NSGCT with elements of embryonal carcinoma, teratoma, and yolk sac tumor. Classified as poor prognosis by the International Germ Cell Cancer Collaborative Group (IGCCCG), he underwent salvage chemotherapy with ifosfamide, paclitaxel, and cisplatin (TIP), followed by radical cystoprostatectomy with pelvic exenteration. At six months post treatment, he remained disease-free with normalized tumor markers. Prostate metastasis from testicular GCTs is an extremely rare event, especially following bilateral, metachronous primaries. This case is unique in demonstrating recurrence with histological elements from both tumors. Aggressive multimodal treatment with TIP, followed by pelvic exenteration, achieved radiological and biochemical response.