Gallbladder polyps ultrasound: what the sonographer needs to know

G Cocco,C Schiavone,A Delli Pizzi,N Anzoletti,G Vallone,R Basilico,P D’Alessandro,N Cocco,D D’Ardes,S Fabiani,F Cipollone,A Boccatonda

doi:10.1007/s40477-021-00563-1

G Cocco, C Schiavone + Show 10 more

Open Access

https://doi.org/10.1007/s40477-021-00563-1

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Abstract

Gallbladder polyps are protuberances of the gallbladder wall projecting into the lumen. They are usually incidentally found during abdominal sonography or diagnosed on histopathology of a surgery specimen, with an estimated prevalence of up to 9.5% of patients. Gallbladder polyps are not mobile and do not demonstrate posterior acoustic shadowing; they may be sessile or pedunculated. Gallbladder polyps may be divided into pseudopolyps and true polyps. Pseudopolyps are benign and include cholesterolosis, cholesterinic polyps, inflammatory polyps, and localised adenomyomatosis. True gallbladder polyps can be benign or malignant. Benign polyps are most commonly adenomas, while malignant polyps are adenocarcinomas and metastases. There are also rare types of benign and malignant true gallbladder polyps, including mesenchymal tumours and lymphomas. Ultrasound is the first-choice imaging method for the diagnosis of gallbladder polyps, representing an indispensable tool for ensuring appropriate management. It enables limitation of secondary level investigations and avoidance of unnecessary cholecystectomies.

Highlights

Gallbladder polyps are elevations of the gallbladder wall projecting into the lumen [1]
We aim to provide sonographers with an ultrasound guide for gallbladder polyps to help interpret whether the polyp is at high or low risk of malignancy and to suggest patient management
Zhang et al argued that Contrast-enhanced ultrasound (CEUS) had a high accuracy for gallbladder sludge and can help in differential diagnosis among gallbladder polyps, adenoma, and cancer; in this series of 105 histologically evaluated gallbladder lesions, CEUS showed sensitivity, specificity, and accuracy of 94.1%, 95.5, and 95.2%, respectively, in the differential diagnosis between benign and malignant lesions, as all the sludge masses were unenhanced throughout the study, polyps and adenomas were mostly homogeneously hyperenhanced in the arterial phase and isoenhanced the venous phase, and tumours usually appeared heterogeneously hyperenhanced in the arterial phase and washed out quickly in the venous phase [35]

Summary

Introduction

Gallbladder polyps are elevations of the gallbladder wall projecting into the lumen [1]. Cholesterolosis appears as parietal hyperechoic single or multiple foci on the gallbladder wall, generating comet-tail artifacts on B-mode and twinkling artifacts on the colour Doppler exam. The differential diagnosis between cholesterol and inflammatory polyps is histological and, for this reason, CEUS is not routinely used These lesions usually appear homogeneous, slightly hyperechoic in the arterial phase and surrounded by normal tissue [18]. The RAS typically appear hypoanechoic, usually observed along with hyperechoic cholesterol crystals or calcifications generating comet-tail reverberation artifacts or acoustic shadowing on B-mode images and twinkling artifacts on colour Doppler images [19–23]. The polyp pattern is the least common, occurring in 15–25% of cases At sonography, it presents as a polypoid parietal lesion projecting towards the lumen with either a homogeneous or heterogeneous echostructure (Fig. 14a). If the gallbladder polyp increases 2 mm or more in size during the ultrasound follow-up, it may be suggestive of malignancy and cholecystectomy is advised [2, 3, 26–28]

Conclusion

Findings

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