Local excision of benign rectal schwannoma using rectal expander-assisted transanal endoscopic microsurgery

Minimizing the surgical approach for a rare disease: transanal endoscopic microsurgery for rectal schwannoma

OBJECTIVE

Rectal schwannomas are extremely rare tumors and their surgical treatment is widely variable in literature. Transanal endoscopic microsurgery (TEM) approach could be a reasonable option for such lesions, offering an organ-sparing strategy, but evidence is scarce.

METHODS

We report a 69-year-old man with a rectal submucosal lesion at 10 cm from the anal verge, treated by TEM. A systematic literature review on surgical approaches in rectal schwannoma was performed.

RESULTS

The patient was successfully treated by TEM, with adequate excision of the submucosal lesion. Histopathology revealed a rectal schwannoma. No recurrence was found at 1-year endoscopic follow-up. Previous studies reported 23 cases of rectal schwannoma and several treatment options, but only 2 cases were treated by TEM. Anterior rectal resection was generally adopted in cases of large, symptomatic masses with inconclusive preoperative biopsy, while lesions with features suggestive of stromal tumors were preferentially treated by endoscopy or, if located in distal rectum, by transanal approaches.

CONCLUSIONS

An organ-sparing minimally invasive approach should be the standard of care for rectal schwannomas. TEM could extend the indication for their endoscopic treatment, providing adequate excision even for larger schwannomas of the middle-upper rectum.

Schwannoma of the colon and rectum: a systematic literature review

Background

Schwannomas of the colon and rectum are rare among gastrointestinal schwannomas. They are usually discovered incidentally as a submucosal mass on routine colonoscopy and diagnosed on pathologic examination of the operative specimen. Little information exists on the diagnosis and management of this rare entity.

The aim of this study is to report a case of cecal schwannoma and the results of a systematic review of colorectal schwannoma in the literature.

Main body

PubMed, Scopus, and Cochrane database searches were performed for case reports and case series of colonic and rectal schwannoma.

Ninety-five patients with colonic or rectal schwannoma from 70 articles were included. Median age was 61.5 years (59% female). Presentation was asymptomatic (28%), rectorrhagia (23.2%), or abdominal pain (15.8%). Schwannoma occurred in the left and sigmoid colon in 36.8%, in the cecum and right colon in 30.5%, and in the rectum in 21.1%. Median tumor size was 3 cm and 56.2% of patients who underwent preoperative colonoscopy had a typical smooth submucosal mass. At pathology, 97.9, 13.7, and 5.3% of schwannomas stained positive for S100, vimentin, and GFAP, respectively. The median mitotic index was 1/50.

Conclusions

Colorectal schwannoma is a very rare subtype of gastrointestinal schwannoma which occurs in the elderly, almost equally in men and women. Schwannoma should be included in the differential diagnosis of a submucosal lesion along with gastrointestinal stromal tumor, neuro-endocrine tumors, and leiomyoma-leiomyosarcoma. Definitive diagnosis is based on immunohistochemistry of the operative specimen. Rarely malignant, surgery is the mainstay of treatment.

Abdominal schwannomas: case report with literature review

Schwannomas are rare tumors that arise from Schwann cells in neural sheaths. They are commonly found in the central nervous system, spinal cord, or peripheral nerves of the body. Occasionally, they occur in the gastrointestinal tract, with the stomach being the most common site. However, colorectal and retroperitoneal schwannomas are very rare. Preoperative diagnosis is often difficult and definitive treatment entails surgical excision. We herein present 3 cases of intraabdominal schwannomas.

Soft tissue tumors of the anorectum: rare, complex and misunderstood

Anorectal soft tissue tumors are uncommon and often present both diagnostic and therapeutic challenges. Although many of these tumors are identified with imaging performed for unrelated reasons, most present with nonspecific symptoms that can lead to a delay in diagnosis. Historically, radical surgery (abdominoperineal resection) has been the mainstay of treatment for both benign and malignant anorectal soft tissue tumors. However, a lack of proven benefit in benign disease along with changes in technology has called this practice into question. In addition, the role of radiation and/or chemotherapy remains controversial. In this manuscript, we review the history and current status of anorectal soft tissue tumor management, with a particular focus on challenges in optimizing survival.

Development of a new operating rectal tube with a side window for transanal endoscopic surgery

The authors describe a new rectal tube for use in transanal endoscopic surgery. The tube is a transparent plastic sheath with its forward end closed, measuring 40 mm in diameter and 150 mm in insert length. It has a window, measuring 40 mm in diameter, on its side. The target lesion, captured within the side window, prolapses into the rectal tube and is excellently visualised without positive pressure gas insufflation. This paper gives details of the tube and reports on a sessile rectal tumour successfully treated using the new system.

Sigmoid schwannoma: A rare case

Schwannomas are rare tumors derived from the cells of Schwann that form the neural sheath. When located in the gastrointestinal tract, they constitute together with leiomyoma, leiomyoblastoma, and leiomyosarcoma, the gastrointestinal stromal tumors (GIST). Peripheral nerve sheath tumors represent 2-6% GIST with most common location, the stomach and the small intestine. Schwannomas of the colon and rectum are extremely rare and radical excision with wide margins is mandatory, due to their tendency to recur locally and become malignant, if left untreated. In the present study, we report a rare case of a sigmoid schwannoma, which was successfully treated in our department and reviewed the literature.