Testis-Sparing Surgery for Multiple Fibrous Pseudotumors of the Epididymis: A Case Report

BACKGROUND Fibrous pseudotumor of the epididymis is a rare benign reactive lesion that accounts for approximately 10% of paratesticular fibrous pseudotumors. Its etiology is unclear but is often associated with trauma or inflammation. Although it is the second most common paratesticular tumor after adenomatoid tumor, its epididymal origin is particularly uncommon. The nonspecific clinical and imaging features frequently lead to a preoperative misdiagnosis of malignancy, potentially resulting in unnecessary radical orchiectomy. CASE REPORT We present the case of a 44-year-old man with a 4-year history of multiple firm, nontender left epididymal nodules. Scrotal ultrasonography showed multiple hypoechoic lesions without testicular invasion, and tumor markers were negative. Intraoperatively, the masses were well-demarcated from the testis, with an intact tunica albuginea, enabling direct testis-sparing complete resection; frozen section was deemed unnecessary. The resected specimen comprised an aggregate 8-cm mass of gray-white nodules. Histopathology revealed a fibrous pseudotumor composed of proliferating fibroblasts and myofibroblasts in a storiform pattern, accompanied by prominent lymphoplasmacytic infiltration. Immunohistochemistry showed an IgG4/IgG ratio <40%, excluding IgG4-related disease. The differential diagnoses of adenomatoid tumor, inflammatory myofibroblastic tumor, and paratesticular sarcoma were ruled out. The patient recovered uneventfully, and at 3-, 6-, and 12-month follow-up no recurrence was observed, with normal testicular morphology and blood flow. CONCLUSIONS This case underscores that when multiple epididymal masses are well-demarcated from the testis, fibrous pseudotumor should be considered, enabling testis-sparing surgery and avoiding unnecessary orchiectomy. Intraoperative frozen section can be a helpful adjunct if the diagnosis is uncertain. Given the benign nature of the lesion, the long-term prognosis is excellent; nonetheless, regular ultrasonographic follow-up is recommended to monitor for potential recurrence.