1528 No Drama: Cap-Assisted Endoscopic Mucosal Resection of an Incidental Colonic Traumatic Neuroma

Abstract

INTRODUCTION: A traumatic neuroma is a well-known complication after acute trauma to a peripheral nerve; the nerve tries to re-establish continuity by an orderly growth of axons from the peripheral to distal stump through the proliferation of Schwann cells. However, this process is not always perfect, and aberrant repair gives rise to a neuroma. CASE DESCRIPTION/METHODS: We present a 50-year-old female who underwent an initial colonoscopy for change in bowel habits and was found to have a 7 mm submucosal lesion in the proximal rectum (Figure 1). She denied any complaints of rectal pain or previous rectal manipulation. Endoscopic ultrasound was done which showed a hypoechoic lesion in the submucosal layer without muscularis propria invasion. The patient underwent successful cap-assisted endoscopic mucosal resection of the lesion without complication (Figure 2). Pathology of the specimen revealed a traumatic rectal neuroma with immunostaining positive for S100 (Figure 3). DISCUSSION: The usual presentation of a traumatic neuroma is of pain, however, our patient presented asymptomatically which can possibly be attributed to the lack of somatic innervation as opposed to neuromas located in an extremity. Interestingly, our patient never had a previous colonoscopy, rectal trauma/manipulation, or rectal intercourse, which could have precipitated a neuroma. In the only other case of a traumatic rectal neuroma, the lesion likely arose as a result of trauma to the submucosal Meissner's plexus fibers or Auerbach's plexus fibers during the polypectomy. To our knowledge, this is the second case of a traumatic rectal neuroma reported in the English literature.