[Sigmoid intussusception as a clinical presentation of colonic schwannoma: Pediatric case]

Comprehensive evaluation of rare case: From diagnosis to treatment of a sigmoid Schwannoma: A case report

BACKGROUND

Schwannomas are uncommon tumors originating from Schwann cells, forming the neural sheath. They account for approximately 2%-6% of all mesenchymal tumors and are most commonly identified in peripheral nerve trunks, with rarity in the gastrointestinal tract. Among gastrointestinal locations, the stomach harbors the majority of nerve sheath tumors, while such occurrences in the sigmoid colon are exceptionally infrequent.

CASE SUMMARY

This study presented a clinical case involving a 60-year-old female patient who, during colonoscopy, was diagnosed with a submucosal lesion that was later identified as a nerve sheath tumor. The patient underwent surgical resection, and the diagnosis was confirmed through immunohistochemistry. This study highlighted an exceptionally uncommon occurrence of a nerve sheath tumor in the sigmoid colon, which was effectively managed within our department. Additionally, a comprehensive review of relevant studies was conducted.

CONCLUSION

The preoperative diagnosis of nerve sheath tumors poses challenges, as the definitive diagnosis still relies on pathology and immunohistochemistry. Although categorized as benign, these tumors have the potential to demonstrate malignant behavior. Consequently, the optimal treatment approach entails the complete surgical excision of the tumor, ensuring the absence of residual lesions at the margins.

A Rare Sigmoid-Colon Schwannoma in a Premenopausal Woman: A Case Report

Background

Schwannomas of the gastrointestinal tract are a rare type of spindle cell tumor of peripheral nerve. Commonly, schwannomas are discovered incidentally, as they are usually asymptomatic.

Case

46-year-old female patient, suffering from secondary amenorrhea and nonspecific intermittent pelvic pain associated with constipation. During gynecological visit an ultrasonographic systematic transvaginal examination was performed. At the sigmoid-rectal level an intraluminal solid mass was described and an urgent colonoscopy was prescribed. Endoscopic submucosal dissection was performed with en-bloc resection. On immunohistochemical analysis, S100 was strongly positive in tumor cells. Finally, a benign schwannoma of the sigmoid colon was diagnosed.

Conclusion

Our case highlights the importance of an adequate transvaginal pelvic examination with the evaluation of all pelvic organs. It could be challenging to make diagnosis in an early stage on asymptomatic patients.

Rare Case of a Transverse Colon Schwannoma

Schwannomas are tumors comprised of schwann cells of the peripheral nervous system and infrequently present in the gastrointestinal tract. Transverse colon schwannomas are an even more rare subtype of gastrointestinal schwannomas. This study presents the case of a transverse colon schwannoma, in addition to presenting a literature review.

Case Report: Schwannoma of the sigmoid colon: a case report of a rare colonic neoplasm and review of literature

Background: Schwannomas are tumors originating in Schwann cells of the peripheral nerve system and uncommonly develop in the gastrointestinal tract. Sigmoid colon schwannomas are very rare and only 28 cases have been reported. This study aims to report a case of a sigmoid colon schwannoma and present a literature review.

Case report: We report a case of a 66-year-old female with asymptomatic sigmoid colon schwannoma. The patient underwent a screening colonoscopy and about 4cm sized submucosal tumor was identified at the sigmoid colon. A colonoscopic biopsy was performed and the microscopic exam revealed an ulcerated lesion with a proliferation of fibroblast-like spindle cells beneath ulcer, which was insufficient for diagnosis. Abdominopelvic computerized tomography (CT) scan showed a well-defined, well-enhancing, round shaped and slightly heterogenous mass at the sigmoid colon. No distant metastasis was identified in abdominopelvic CT and chest CT scans. Carcinoembryonic antigen level was within a normal range (1.33ng/mL). The patient underwent laparoscopic anterior resection. Immunohistochemical staining of the resected specimen showed positivity for S-100 protein in tumor cells and schwannoma was diagnosed post-surgically. Surgical resection margins were free from tumor and no regional lymph node metastasis was reported.

Conclusion: Colon schwannomas are rare diseases. Most cases of colon schwannomas are accidentally identified during screening colonoscopy. The tumors usually present as submucosal masses and colonoscopic biopsies are mostly non-diagnostic. Surgical resection is required, and definitive diagnosis is made by confirming S-100 positive tumor cells in immunohistochemical analysis. Most cases are benign; a few cases have been reported to be malignant. Surgical resection with free negative margins is the treatment of choice