EUS-Elastography and Contrast in the differential diagnosis of SELs: update of an Italian multicenter study

Aims The prevalence of subepithelial lesions (SELs) is increasing, and although conventional endoscopic ultrasonography (EUS) provides much detail, tissue acquisition is often still essential to reach a diagnosis, which is nonetheless technically challenging. To overcome this difficulty, the use of elastography (EUS-E) and contrast-enhanced harmonic-EUS (CH-EUS) has already proven useful in other contexts, but for SELs, supporting data are still preliminary. The purpose of this study is to examine the performance of EUS-E and CH-EUS in the differential diagnosis of SELs.

Methods From March 2021 to August 2024, all patients referred to 5 Italian reference institutions for fine-needle biopsy (FNB) of a SEL were prospectively enrolled: EUS-E (qualitative and semiquantitative with SR calculation) and CH-EUS were performed before biopsy. Based on the integrated EUS assessment, providers were asked to make a prediction about the diagnosis, and a dataset of standardized EUS-E and CH-EUS features was created and matched to the final diagnosis. The sensitivity (Se), specificity (Sp) and accuracy (Ac) of these features were calculated.

Results A total of 96 lesions were collected, with a median size of 27.5 mm (IQR 20-41). 63 were found in the stomach, 30 in the esophagus or duodenum. All were solid, 84 were from the muscolaris propria, and 88 were hypoechoic. The final diagnosis showed 66 GISTs, 18 leiomyomas and 12 lipomas, NETs, Shwannoma and other lesions. Overall, the operator's diagnostic hypothesis was correct in 78.0% of cases, with an Ac in predicting GISTs of 86.1% (Se88.2%, Sp80.3%). Qualitative E-EUS (stiff-blue) showed an Ac in predicting GISTs of 61% (Se66.4%, Sp44.9%) and 63.6% (Se48.2%, Sp67.5%) in the diagnosis of leiomyoma (mixed-green pattern); at semiquantitative evaluation, GISTs had a mean SR of 21.5 while leiomyomas had a mean SR of 11.1 (p<0.05). Contrast hyperenhancement had an Ac in the diagnosis of GISTs of 73.0% (Se87.9%, Sp40.5%) while hypoenhancement of 79.8% (Se55.0%, Sp85.1%) in the diagnosis of leiomas; GISTs were hyperenhancement in 87.3% of cases while leiomas in 50% (p<0.001). High Sp levels in the diagnosis of GISTs were achieved in the presence of avascular areas (80.2%) or with the previously reported SR cut-off of 22.7 (92.9%). The only Shwannoma in the cohort was misdiagnosed as GIST, being hypervascular, but without avascular areas and with an SR greater than 50.

Conclusions The application of integrated EUS allows high levels of Ac in the differential diagnosis of SELs, and in particular the contrastographic study and the application of semiquantitative elastography allow high levels of Sp. This approach would then allow biopsy to be “spared” in lesions without malignant potential (leiomyomas), reserving its use in doubtful cases or for lesions with malignant potential (predominantly GISTs), in which it is recommended for immunohistochemical and mutational study on which subsequent management is determined.

Publication History

Article published online:
27 March 2025