Endoscopic approach to subepithelial lesions.

Endoscopy and endoscopic ultrasound (EUS) play a critical role in the detection and management of subepithelial lesions of the gastrointestinal tract. The most common subepithelial lesions detected by endoscopists are gastrointestinal stromal tumors (GISTs), leiomyomas, lipomas, granular cell tumors (GCTs), pancreatic rests and carcinoid tumors. These lesions can be classified based on unique histochemical staining and the gastrointestinal layer of origin. While the majority of the lesions are considered benign, some tumors such as GISTs and carcinoids have a strong propensity for malignant transformation. Therefore, appropriate endoscopic versus surgical management based on size and location is crucial in the prevention of malignant transformation and metastasis. In this review, we provide a systematic approach to the diagnosis, management and treatment of commonly encountered subepithelial lesions.