Ultrasound Imaging Features Associated With Neoplastic Gallbladder Polyps: A Systematic Review and Meta-Analysis

OBJECTIVE: Although most gallbladder polyps are benign, some neoplastic polyps may be malignant or may serve as precursors to malignancy. Distinguishing neoplastic and non-neoplastic polyps using imaging examinations remains a major challenge. This meta-analysis aimed to identify the ultrasound (US) features that are significantly associated with neoplastic polyps. MATERIALS AND METHODS: The MEDLINE, EMBASE, Cochrane, and KoreaMed databases were searched for articles published up to August 31, 2025. Bivariate random-effects models were used to calculate the meta-analytic pooled diagnostic odds ratios (DORs), sensitivities, and specificities, along with their 95% confidence intervals (CIs), for each US imaging feature in the diagnosis of neoplastic polyps. RESULTS: Thirty studies evaluating 8,953 patients, including 1,216 (13.6%) patients with neoplastic polyps, were included. Among the nine evaluated US imaging features, namely, size ≥10 mm, sessile morphology, single polyp, coexisting gallstones, hypoechogenicity, heterogeneous echogenicity, gallbladder wall thickening (GBWT), absence of hyperechoic spot, and vascularity, eight were significantly associated with neoplastic polyps: size ≥10 mm (DOR: 6.23 [95% CI: 1.86-20.90]), sessile morphology (DOR: 3.54 [1.93-5.97]), single polyp (DOR: 2.21 [1.76-2.74]), coexisting gallstones (DOR: 1.86 [1.29-2.60]), hypoechogenicity (DOR: 3.55 [1.47-7.30]), GBWT (DOR: 9.38 [1.47-32.20]), absence of hyperechoic spots (DOR: 4.23 [2.46-6.83]), and vascularity (DOR: 9.72 [5.81-15.30]). Of these, size ≥10 mm demonstrated the highest pooled sensitivity (0.79 [95% CI: 0.68-0.87]), whereas hypoechogenicity showed the highest pooled specificity (0.93 [95% CI: 0.82-0.98]). CONCLUSION: Eight US imaging features (size ≥10 mm, sessile morphology, single polyp, coexisting gallstones, hypoechogenicity, GBWT, absence of hyperechoic spots, and vascularity) were significantly associated with the presence of neoplastic polyps. These features may facilitate the management of gallbladder polyps.