A Case of Presacral Low Grade Fibromyxoid Sarcoma

Abstract

Low grade fibromyxoid sarcoma (LGFMS) is a rare soft-tissue tumor showing such malignant clinical features as a high metastasizing potential and sometimes long interval between tumor presentation and metastasis. We report a recent case of intrapelvic LGFMS.

A 43-year-old man presented to our hospital because of abnormal bowel movement. An abdominal contrast-enhanced CT scan revealed an about 11-cm tumorous lesion on the pelvic surface of sacrum. Preoperative transrectal needling biopsy failed to make the definite diagnosis. We performed the tumor extirpation through the transsacral and transabdominal approach by keeping the dissected margins, followed by low anterior resection of rectum. Histopathology disclosed the tumor to be concomitantly composed of fibrous and myxoma-like components. Immunostaining showed MUC4 positive. Accordingly, LGFMS was diagnosed. The patient's postoperative course was uneventful, and no recurrence has occurred as of 3 years after the operation.

Although presacral LGFMS is extremely rare, it must be kept in mind as a possible differential diagnosis and a long-term follow-up is mandatory because it takes a long time until metastasis.