Large liposarcoma developing in the ischiorectal fossa: Report of a rare case

INTRODUCTION: We herein report an extremely rare case of a liposarcoma developing in the ischiorectal fossa that was completely resected using a transsacral approach. PRESENTATION OF CASE: A 74-year-old man was admitted to our institute because of a large perianal tumor. A pelvic magnetic resonance imaging (MRI) revealed an 8 cm × 7 cm × 5 cm sized encapsulated heterogeneous tumor on the right side of the ischiorectal fossa. Transsacral excision was performed under a diagnosis of liposarcoma. The tumor was partially fixed to the external sphincter and puborectalis. Therefore, the muscles were partially resected to ensure sufficient margins. Histopathological examination revealed a well differentiated liposarcoma and negative surgical margins. DISCUSSION: The basic treatment strategy of liposarcoma is surgical resection, whereas the effects of chemotherapy or radiotherapy remain limited. Although no postoperative adjuvant therapy has been performed in our case, no recurrences have occurred for 1 year after surgery. CONCLUSION: Although the curative resection of large tumors located in the ischiorectal fossa is usually difficult, the complete resection of liposarcoma is the main potentially curative treatment. A transsacral approach is useful for a complete resection.