Cap-Assisted Endoscopic Mucosal Resection of an Incidental Rectal Traumatic Neuroma

Case Reports in Gastrointestinal Medicine
08 Nov, 2019 ,

This is a case of 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. Endoscopic ultrasound was done which showed a hypoechoic lesion in the submucosal plane without muscularis propria invasion. The patient underwent successful cap-assisted endoscopic mucosal resection of the lesion without complication. Pathology of the specimen revealed a traumatic rectal neuroma with immunostaining positive for S100.

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A 50-year-old female with a past medical history of asthmatic bronchitis underwent an initial colonoscopy procedure after complaining of 3 weeks of loose nonbloody bowel movements. The patient denied any rectal pain or prior rectal manipulation. On colonoscopy, an incidental 7 mm submucosal nodule was seen in the proximal rectum at 12 cm from the anal verge.

The initial endoscopic biopsies taken from this area, however showed unremarkable rectal mucosa on histology. She then underwent an endoscopic ultrasound (EUS) of the localized submucosal lesion located 12 cm from the anal verge, at the 3 o’clock position.

The lesion was homogenously hypoechoic, measuring up to 13 mm in thickness. The lesion was contained within the submucosal plane without muscularis propria invasion. The decision was made to pursue a cap-assisted endoscopic mucosal resection with an adult endoscope. A Carr-locke needle was used to inject approximately 5 ml of a mixture of saline and methylene blue, which provided an adequate lift of the lesion from the muscularis propria layer. An en bloc endoscopic mucosal resection with a cap and snare was achieved. Two hemostatic clips were placed to close the mucosal defect.

 The resected specimen was examined, showing no muscular fibers. Pathology of the specimen revealed a well-circumscribed 4 mm submucosal traumatic neuroma comprised of haphazardly proliferating spindle cells consistent with Schwann cells embedded in a fibrous stroma. Immunostaining was positive for S100. The patient tolerated the procedure well and had no complications on one-month follow-up.