Single Epididymis Metastasis 12 Years After Radical Prostatectomy: A Case Report and Literature Review

Introduction: Metastatic spread of prostate cancer to the epididymis is exceptionally rare. Recognition is challenging because clinical and ultrasonographic findings may mimic benign or primary paratesticular lesions. Case presentation: We describe a 71-year-old man who developed an isolated epididymal metastasis 12 years after radical prostatectomy for high-risk prostate cancer. After adjuvant treatment and later biochemical recurrence managed with salvage radiotherapy and androgen deprivation therapy, prostate-specific antigen rose to 2.2 ng/mL despite castrate testosterone levels. Choline positron emission tomography/computed tomography identified a suspicious paratesticular lesion. Scrotal ultrasound showed a cystic mass initially suggestive of a benign epididymal lesion. Surgical exploration with hydrocelectomy and excision of the epididymal mass was performed for both diagnostic and therapeutic purposes. Histology and immunohistochemistry confirmed metastatic adenocarcinoma of prostatic origin. After surgery, prostate-specific antigen became undetectable. Conclusion: This case underlines the need to consider epididymal metastasis during follow-up when prostate-specific antigen rises without typical sites of relapse and supports the role of dedicated scrotal evaluation, molecular imaging, and individualized surgical management in selected patients.