A case of benign schwannoma of the ascending colon treated with laparoscopic-assisted wedge resection.

Isolated colonic schwannomas are rare gastrointestinal mesenchymal tumors. Only a small number of cases have been reported. Occurrence of these tumors is more common in the stomach than in the large intestine. These spindle cell lesions are distinct from leiomyoma, leiomyosarcoma, and gastrointestinal stromal tumors because the tumor cells have a distinct immunophenotype, with strong diffuse positivity for S-100 and vimentin, as well as corroborative negative staining of CD117 and smooth muscle markers. We present a case of colonic schwannoma in a 70-year-old woman who had no specific symptoms. The patient was diagnosed with a submucosal tumor in the ascending colon on colonoscopy and abdominal computed tomography. Laparoscopic-assisted wedge resection of colon was performed. The very rare pathologic diagnosis of ascending schwannoma was made postoperatively. This case is interesting because schwannomas of the colon and rectum are extremely rare and are treated by laparoscopic-assisted wedge resection.