Epididymal leiomyosarcoma: a case report.

BACKGROUND: Epididymal leiomyosarcoma is a rare, malignant neoplasm (Fisher et al. in Am J Surg Pathol 25(9):1143–9, 2001) characterized by rapid growth and aggressive behavior. Over the past decade, fewer than 30 cases of epididymal leiomyosarcoma have been reported globally. CASE PRESENTATION: In 2024, a male presented to the Fourth Affiliated Hospital of Zhejiang Universityl with a left scrotal mass. The patient underwent scrotal ultrasound and pelvic MRI, initially diagnosed with a hypervascular tumor of the epididymis; however, the precise nature of the tumor remained indeterminate before surgery. Following radical orchiectomy, postoperative pathology confirmed the diagnosis of epididymal leiomyosarcoma. CONCLUSION: Although epididymal leiomyosarcoma represents a rare entity, it should be included in the differential diagnosis when patients present with a progressive scrotal mass demonstrating characteristic imaging features of diffusion restriction, heterogeneous hypoechogenicity, and hypervascularity. Notably, despite the well-demarcated contours and regular configuration of early-stage lesions, radical orchiectomy should be strongly recommended over simple epididymectomy given the tumor’s aggressive biological behavior. Simple epididymectomy is associated with higher recurrence rates. Long-term, rigorous surveillance remains paramount for disease management.