Management of Gastrointestinal Schwannomas: A State-of-the-Art Review

Gastrointestinal schwannomas are rare mesenchymal tumors that arise from the Schwann cells of the enteric nervous system, representing a unique clinicopathological entity among subepithelial lesions of the gastrointestinal tract. The aim of this state-of-the-art review is therefore to analyze the specific clinicopathological characteristics of these rare tumors as well as to better understand the appropriate diagnostic tools and therapeutic approaches where these are required.

This review combines findings from large series studies to provide a complete analysis of gastrointestinal schwannomas, even those with unusual locations.

Despite the typical occurrence of these tumors within the stomach, they can occur throughout the gastrointestinal tract, from the esophagus, small intestine, colon, rectum, through to the mesentery, presenting a diagnostic dilemma. Due to the non-specific presentation, radiological, and endoscopic similarities between schwannomas and gastrointestinal stromal tumors (GISTs), a preoperative misdiagnosis is common. Recent improvements in immunohistochemistry have helped to define their biological identity based on widespread staining for S100/SOX10 with absence of KIT/DOG1 mutations. While techniques such as contrast-enhanced CT scans as well as endoscopic ultrasonography have certain diagnostic advantages, they are not sufficient to make a diagnosis without histopathological validation. Surgical resection is considered the mainstay of therapy, addressing both purposes. Endoscopic methods have been adopted for smaller lesions in more favorable locations, while surgical resection is considered standard for larger or more complex lesions.

Despite their rarity, early and accurate diagnosis is important to avoid unnecessary interventions when conservative management may be appropriate. When treatment is required, resection strategies should be tailored to tumor characteristics.