High Grade Leiomyosarcoma Mimicking a Recurrent Angiomyxoma in the Perineum

Abstract

Perineal leiomyosarcoma is an extremely rare and aggressive cancer with a high metastatic potential and no defined standard treatment. There are only a few (six) reported cases in the literature. We report the case of a 67-year-old woman with a perineal leiomyosarcoma arising at the same site of a previously resected superficial angiomyxoma. Initially, she was treated for a presumptive recurrence of angiomyxoma. As she did not respond to medical therapy, she underwent repeat surgical excision. Pathology revealed a high grade leiomyosarcoma, histologically strikingly distinct from the initial diagnosis. She received adjuvant local radiation therapy, and remains without evidence of recurrent disease 36 months after completion of all therapy. This is the first reported case of a high grade perineal leiomyosarcoma originating at the same site as a resected benign superficial angiomyxoma. Our case emphasizes the necessity of a prompt histological diagnosis in cases of presumed recurrent perineal angiomyxoma.

Rare case of giant ischiorectal leiomyosarcoma

“…Soft tissue sarcomas are rare cancers with an annual incidence of <5 per 1000,000 [ 3 ]. Around 5 to 10 % of all soft tissue sarcomas are leiomyosarcoma [ 8 ].…”

“…Size larger than 5 cm (giants) are even rarer and only little have been reported in the literature [ 2 ]. The uterus and retroperitoneum were reported to be the most common anatomical sites for leiomyosarcomas [ 3 ]. Ischiorectal fossa is a space bounded anteriorly by anterior perineum, posteriorly by sacrotuberous ligament with gluteus maximus muscle, and laterally by ischial tuberosity with obturator internus muscle [ 4 ].…”