Preliminary data from a multicenter Italian study: use of EUS-Elastography and Contrast in the differential diagnosis of SELs

Aims Distinguishing gastrointestinal subepithelial lesions (GI-SELs) poses a clinical challenge because Endoscopic Ultrasound (EUS) is adept at detecting them but may fall short in providing effective differentiation. New methodologies have been introduced which provide further details and potential prognostic information. Elastography (EUS-E) allows to carry out a qualitative and semi-quantitative assessment of tissue stiffness, but for now only a few studies have examined its role in the diagnosis of SELs. Recent findings indicate that contrast agents enhance the diagnostic accuracy of EUS (CE-EUS) for SELs. The purpose of the study is to examine the performance of the EUS-E and CE-EUS in differentiating GI-SELs, and in particular gastrointestinal stromal tumors (GISTs).

Methods From March 2021 to June 2023, all patients referred to 4 Italian Institutions for EUS-guided fine needle biopsy (FNB) of GI-SELs who agreed to participate in the study were prospectively enrolled. Endosonographic patterns were compared with the analysis of the histological samples taken through FNB or subsequent endoscopic/surgical resection. Sensitivity (Se), specificity (Sp) and accuracy (Ac) of an increasing number of variables in the diagnosis of GIST were then evaluated.

Results We present the data of the first 56 enlisted patients. The cohort had a balanced M:F ratio of 1, with a median age of 65 years (range: 26-85). Lesions’ median size was 29 mm (12-90), 38 were detected in the stomach, while 9 in the duodenum and 9 in the esophagus. All lesions were solid and 51 of them originated from the muscolaris propria, 52 were hypoechoic. Qualitative elastography (based on color) revealed homogeneous blue (stiff) lesion in 40 cases, 1 green (soft) lesion and 15 mixed lesions. During contrast infusion, 40 lesions showed hyper-enhancement, 9 hypo-enhancement and 7 iso-enhancement; contrast distribution was evaluated as inhomogeneous in 32 cases. Final diagnosis showed 38 GISTs, 10 leiomyomas and 8 among lipomas, NETs and others. The basic characteristics of EUS (origin 4^th layer and hypo-echogenicity) have a Se, Sp and Ac of 94,7%, 22,2% and 71,5% respectively; qualitative elastography showed Se, Sp and Ac of 71,1%, 44,4% and 62,5% respectively; elastography plus CE-hyperenhancement corresponded to Se, Sp and Ac of 61,1%, 66,7% and 63,0%; and if contrast diffusion was also evaluated as inhomogeneous Se, Sp and Ac were 41,7%, 83,3% and 55,5% respectively. [1] [2] [3] [4]

Conclusions Our findings indicate that EUS alone is highly sensitive and reasonably accurate in detecting GISTs, albeit lacking specificity. However, when dealing with a lesion that raises suspicion for GIST, employing certain enhancing EUS techniques can significantly enhance specificity. This can be of help in the decision-making process, especially where a biopsy is not technically easy to obtain, but, in the concrete suspicion of a GIST, it is of fundamental importance to obtain it.

Publikationsverlauf

Artikel online veröffentlicht:
15. April 2024

• References

• 1 Pesenti C, Bories E, Caillol F. et al. Characterization of subepithelial lesions of the stomach and esophagus by contrast-enhanced EUS: A retrospective study. Endoscopic Ultrasound 2019; 8: 43-49
• 2 Vasilakis T, Ziogas D, Tziatzios G. et al. EUS-Guided Diagnosis of Gastric Subepithelial Lesions, What Is New?. Diagnostics (Basel) 2023; 13: 2176
• 3 Pallio S, Crinò SF, Maida M. et al. Endoscopic Ultrasound Advanced Techniques for Diagnosis of Gastrointestinal Stromal Tumors. Cancers (Basel) 2023; 15: 1285
• 4 Study code: SUNNYDAY 021-FPO20