Case Report: An extremely rare occurrence of recurrent inguinal low-grade fibromyxoid sarcoma involving the scrotum.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare sarcoma subtype. The most common tumor locations are the deep soft tissue of extremities or trunks. We report a rare case of recurrent LGFMS in the inguinal region involving the scrotum and both testicles. A 38-year-old male patient reported a history of multiple nodular lesions in the left inguinal region accompanied by local inflammation. The patient was submitted for local resection of the lesion at our institution, with histopathological diagnosis of LGFMS. He missed his follow-up, returning with a large bulge in the left inguinal region involving the scrotum with signs of tissue necrosis and local purulent discharge. Surgical exploration was performed and the patient underwent tumor resection in the left inguinal region and the entire scrotum, with bilateral orchiectomy, with the margins enlarged to the right inguinal region and proximal surface of the penis. Local reconstruction was performed with a left fascia lata tensor muscle flap and ipsilateral thigh coverage using partial skin graft. On microscopic examination, the tumor showed spindle cells arranged in bundles, with abundant collagen and myxoid stroma with interspersed prominent vessels. The immunohistochemical study carried out showed immunoreactivity with Ki67 (<5%), immunonegativity with desmin and S100, confirming the diagnosis of LGFMS. Postoperative recovery was good and no recurrence was seen after two years. The patient is in good health, realizing multidisciplinary outpatient follow-up and performing continuous testosterone replacement. Surgical resection with negative margins for localized disease remains the standard treatment for LGFMS.