Gastrointestinal: asymptomatic colonic schwannoma in an elderly woman; a rare case

Schwannoma of the Ascending Colon in a 22-Year-Old Male: A Case Report

Schwannoma of the ascending colon is an extremely rare neoplasm that is often discovered incidentally in the asymptomatic older population on surveillance colonoscopy. We present the case of a symptomatic 22-year-old male presenting with one month of discomfort in the right lower abdominal quadrant, abdominal bloating, and hematochezia. A sessile polyp measuring 0.5 cm was identified in the ascending colon on the colonoscopy. The polyp was completely resected using cold snare polypectomy. Histological examination of the resected polyp with hematoxylin-eosin staining revealed small nodules of bland spindle cells with focal nuclear condensation. The lesional cells tested positive for S-100 and SOX-10 on immunohistochemical analysis, establishing the diagnosis of benign schwannoma. Since this lesion was submucosal, its diagnosis required an endoscopic biopsy that could only be performed on the mucosa. It was difficult to distinguish it from other mesenchymal tumors (gastrointestinal stromal tumor or leiomyoma), and this makes the differential diagnosis exceedingly challenging. If the immunohistochemistry is positive for S-100 and negative for C-KIT, CD-34, actin, and desmin, it aids in diagnosis. These tumors have non-specific radiological features and are asymptomatic.

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.

Peritumoral lymphoid cuff correlates well with lymph node enlargement in gastrointestinal schwannomas

Background/Aims

To determine the incidence of regional lymphadenopathy in gastrointestinal (GI) schwannoma and to evaluate the relationship between peritumoral lymphoid cuff and lymphadenopathy.

Methods

We queried 118 GI tract schwannomas and reviewed radiologic findings, intraoperative findings, and electronic medical records of all cases for enlarged regional lymph nodes.

Results

Location of tumors included 85 gastric (72%), 11 colonic (9.3%), 7 esophageal (5.9%), 3 pancreatic (2.5%), 1 hepatic (0.8%), and 11 mesenteric (9.3%). The size of the tumors ranged from 0.2 to 11 cm (mean 3.8 cm). Histologically, 70.3% showed a peritumoral lymphoid cuff ranging in thickness from 0.3 to 6 mm (mean 1.6 mm). The peritumoral lymphoid cuff was significantly more frequent in gastric schwannomas (78.8%) followed by colonic (72.7%), esophageal (57.1%) and rare in other locations (p = 0.001). Of the 106 cases for which clinical or radiologic data was available for, 76 cases (71.7%) showed regional lymphadenopathy. The presence of peritumoral lymphoid cuff showed significant correlation with regional lymphadenopathy (p < 0.001) and the size of enlarged lymph nodes (p = 0.002).

Conclusions

A peritumoral lymphoid cuff is frequently seen in GI tract schwannomas and correlates well with regional lymphadenopathy. However, in a significant subset (29.7%), a lymphoid cuff was not present warranting continued need for caution in the preoperative radiologic and postoperative pathologic diagnoses.

Schwannoma of the colon: A case report and review of the literature

Colonic schwannomas are rare gastrointestinal mesenchymal tumors, and only a limited number of cases has been reported. The occurrence of these tumors is less common in the large intestine than in the stomach. The present study reports a case of colonic schwannoma in a 62-year-old female patient with no specific symptoms. The patient was diagnosed with a mass in the ascending colon by colonoscopy and abdominal computed tomography scanning. A right hemicolectomy was performed. The postoperative pathological diagnosis was ascending schwannoma. This case is noteworthy as colonic schwannomas are rare and are typically treated as colon cancer. No recurrence of the lesion was observed after 24 months of follow-up.