EUS-Elastography and Contrast-Enhanced EUS Diagnostic Accuracy in the Differential Diagnosis of Subepithelial Gastrointestinal Tumors: a Multicenter Prospective Observational Study

The differentiation among the Gastrointestinal Subepithelial Tumors (SETs) represents a clinical challenge. Endoscopic Ultrasound (EUS) alone may be ineffective in differentiating SETs subtypes, and tissue sampling of these lesions may be technically difficult. EUS Elastography (EUS-E) has been applied to many gastrointestinal diseases, providing a qualitative/semi-quantitative stiffness analysis, but only few studies have examined the role of EUS-E in the diagnosis of SETs. In addition, the use of contrast agents has improved the diagnostic performance of the EUS, especially in the differentiation between GISTs and other gastrointestinal SETs.

The aim of the study is to examine the performance of EUS-E and Contrast Enhanced-EUS (CE-EUS) in distinguishing among different gastrointestinal SETs subtypes. EUS patterns of different techniques will be compared to the final diagnosis gained by the analysis of histopatological specimens (surgical resection or EUS-FNB) or imaging/clinical follow-up.