Endoscopic submucosal excavation of a rectal submucosal tumor assisted by a curvilinear echoendoscope

A 62-year-old woman undergoing screening colonoscopy was found to have a submucosal protrusion in the mid-rectum. Evaluation with a curvilinear echoendoscope revealed it to be a 1.8×1.1cm, hypoechoic mass originating from muscularis propria (MP) . Endoscopic submucosal excavation (ESE) was attempted, but despite adequate dissection of the submucosa, the mass remained poorly defined appearing as a slight elevation in the background of flat muscle. Repeat visualization of the lesion status post submucosal dissection was performed with the curvilinear echoendoscope. A biopsy forceps was introduced as a movable landmark which could be visualized on both synchronized endosonographic and optical views, so as to clearly identify the margin of the lesion . Incision of the MP overlying the identified margin allowed for precise exposure of the mass, which was further excavated and finally resected.