A CASE OF PARARECTAL DESMOID TUMOR IN WHICH ENDOSCOPIC ULTRASOUND WAS USED FOR PREOPERATIVE DIAGNOSIS AND DECISION-MAKING ABOUT APPROPRIATE TREATMENT

Abstract

A 67-year-old man was referred to our hospital for further examination of a tumor in the pelvis. CT scan revealed a tumor of 25mm in diameter located close to the anterior wall of the rectum. We could not determine whether the tumor was adhered to the rectum by CT scan and MRI. FDG-PET scan showed slight uptake in the mass, and we made the diagnosis of a low-grade malignant tumor such as a desmoid tumor and planned surgical resection. However, EUS showed a movable tumor with a uniformly low echoic level that was adjacent to the rectum. We therefore changed the surgical procedure from lower anterior resection of the rectum to transperineal resection of the tumor and its pathological diagnosis was a desmoid tumor. EUS was useful for making the preoperative diagnosis and the decision of appropriate treatment in this case.