A Comparative Analysis of GISTs and Schwannomas in the Sigmoid Colon: Case Report and Review of the Management Strategies.

Background/Objectives: Mesenchymal tumors of the gastrointestinal tract are rare and can pose significant diagnostic challenges, particularly when located in atypical sites such as the sigmoid colon. Gastrointestinal stromal tumors (GISTs) are often the primary consideration based on imaging findings; however, other spindle cell neoplasms, such as schwannomas, must also be considered. We present a case of a sigmoid colon schwannoma initially suspected to be a GIST and provide a literature review on the diagnostic and therapeutic challenges associated with these tumors. Methods: A literature review based on articles from 2015 to 2024 was conducted to identify cases of mesenchymal tumors of the colon misdiagnosed as GISTs. The review focused on the role of imaging, endoscopic biopsy, and immunohistochemistry in differentiating these neoplasms. Additionally, treatment approaches, including surgical resection versus targeted therapy, were assessed. Results: The literature review revealed that GISTs and schwannomas share overlapping imaging characteristics, including submucosal location, hyperintensity on T2-weighted MRI, and contrast enhancement. However, immunohistochemical markers remain the gold standard for differentiation. Studies also highlighted the increasing role of minimally invasive diagnostic techniques, such as fine-needle aspiration and molecular profiling, in achieving a definitive preoperative diagnosis. Unlike GISTs, which often require adjuvant therapy with tyrosine kinase inhibitors, schwannomas are typically treated with surgical excision alone, with a low risk of recurrence. Conclusions: Current evidence supports a multimodal diagnostic approach combining imaging, biopsy, and immunohistochemistry to accurately classify mesenchymal tumors of the colon. While imaging can suggest a probable diagnosis, histopathological confirmation is essential before initiating targeted therapy.