Metastasis of primary testicular leiomyosarcoma to the retroperitoneal space

A 70-year-old man presented with a left scrotal swelling. A computed tomography scan showed an 8-cm left scrotal mass and no metastasis. Radical orchiectomy with high ligation of the spermatic cord was performed. The tumor was classified as a high-grade leiomyosarcoma of the left testis. An intensive follow-up including repeated computed tomography scans was performed. A computed tomography scan 34 months after the surgery showed a retroperitoneal mass in front of the left kidney. Resection of the mass was performed. Microscopically, the mass was metastatic leiomyosarcoma. Intratesticular leiomyosarcoma is rare; only 18 cases have been reported. This is the first case in which leiomyosarcoma metastasized to the retroperitoneal space postoperatively. We herein review the literature and discuss how intratesticular leiomyosarcoma metastasized to the retroperitoneal space in this patient.