Endoscopic Ultrasonographic Features of Subacute Radiation Proctitis

Abstract

Endoscopic ultrasonography (EUS) is one of the most accurate methods for the assessment of rectal disorders, in particular for local staging of rectal adenocarcinomas. 1 The role of EUS in imaging benign inflammatory disorders of the rectum is less defined. 2-4 Radiation proctitis is a known complication of pelvic irradiation. Acute radiation proctitis occurring within the first 6 weeks is caused by direct mucosal damage by radiation and typically resolves with resolution of the radiation treatement. 5,6 Chronic radiation proctitis is a result of progressive epithelial atrophy, fibrosis, and obliterative endarteritits with mucosal ischemia. It manifests late (>1 year after radiation) in 5% to 20% of patients, with symptoms including rectal bleeding, pain, and urgency. 7 The risk of rectal adenocarcinoma is increased after pelvic radiation therapy; however, the rate does not increase for 10 to 20 years after therapy. 8 In this report, we present an unusual case of subacute radiation proctitis appearing as an ulcerated mass lesion and the use of EUS to help differentiate it from malignancy. To our knowledge, the EUS features of radiation proctitis have not been reported previously.