Background: Endoscopic ultrasonography (EUS) is commonly agreed to be the best imaging method for diagnosing and differentiating between submucosal lesions in the gastrointestinal tract. However, most of the current evidence for this derives from retrospective multicenter studies. A prospective multicenter analysis of the performance of EUS in diagnosing submucosal lesions in everyday practice was therefore conducted.
Methods: Over a 2-year period, this study included 150 patients (52% men, mean age 59.8 years) from 23 centers who had a presumptive diagnosis of a submucosal lesion on upper gastrointestinal endoscopy. The patients' symptoms and EUS results were recorded. Endoscopic and endosonographic findings regarding lesion size, layer of origin, and the presumptive diagnosis (benign or malignant) were recorded. The reference methods used were surgery, biopsy, other imaging tests, and a follow-up period of 6 months.
Results: Of the 150 patients, 102 had an intramural lesion (84 tumors, 18 other lesions such as cysts, aberrant pancreas, etc.), and 48 had an extraluminal compression--in most cases (n = 35) by normal organs or structures. For differentiating between a submucosal and an extraluminal compression, the sensitivity and specificity of endoscopy were 87% and 29%, whereas those of EUS were 92% and 100%. However, the sensitivity and specificity of EUS for differentiating between malignant and benign submucosal tumors were only 64% and 80%, respectively.
Conclusions: The accuracy of EUS in differentiating between submucosal tumors and extraluminal compressions is substantially superior to that of endoscopy, but EUS is still inadequate for differential diagnosis between benign and malignant submucosal tumors. However, EUS is still the best method of visualizing submucosal lesions precisely. The influence of EUS on the further management in these patients remains to be examined in subsequent studies.