Efficacy of Contrast‐Enhanced Endoscopic Ultrasound in the Diagnosis of Gallbladder Tumor: A Retrospective Multicenter Cohort Study

BACKGROUND AND AIMS Contrast-enhanced endoscopic ultrasonography (CE-EUS) provides clearer visualization of wall layer structures in gallbladder nodules than B-mode EUS. This study aimed to compare the diagnostic performance of B-mode EUS and CE-EUS in differentiating benign from malignant gallbladder lesions.

METHODS Patients who underwent both B-mode EUS and CE-EUS for gallbladder nodules with available pathological diagnoses were retrospectively analyzed. The diagnostic findings of each modality were evaluated by univariate and multivariate analyses.

RESULTS Eighty-six patients were included (31 malignant, 55 benign). On B-mode EUS, a pedunculated shape and presence of a Rokitansky-Aschoff sinus were associated with benignity, whereas diameter ≥ 20 mm and an unclear or disrupted wall layer structure were associated with malignancy. On CE-EUS, unclear or disrupted wall layer structure was strongly associated with malignancy, whereas enhancement patterns showed only univariate significance. Multivariate analysis identified unclear or disrupted wall layer structure on CE-EUS and diameter ≥ 20 mm as independent predictors of malignancy. Diagnostic accuracy was significantly higher with CE-EUS evaluation of wall layer structure (93%) than with B-mode EUS evaluation of maximum diameter (78%, p < 0.001).

CONCLUSION CE-EUS, particularly assessment of wall layer structure, improves differentiation between benign and malignant gallbladder nodules and complements B-mode EUS.