Transverse colon schwannoma treated by endoscopic mucosal resection: A case report.

Gastrointestinal (GI) schwannoma is one of the rarest tumors of the GI tract. We herein describe the case of a 70-year-old female patient who presented for surveillance colonoscopy. The examination detected a 1-cm polyp that was removed by snare cautery polypectomy. Immune and histochemical staining revealed spindle cells that were positive for S-100 and vimentin, but negative for CD34 and smooth muscle actin, consistent with GI schwannoma. This case is noteworthy as GI schwannomas usually present in the stomach, making the finding of a colonic schwannoma of clinical interest. Furthermore, the present case was treated by removing the tumor endoscopically, in contrast to more invasive methods.