Gallbladder polyp (polypoid lesion)

Ultrasound-detected gallbladder polyps are common and mostly cholesterol polyps or adenomyomatosis rather than true neoplasms. A systematic review of 5,482 polyps found 0.57 percent malignant and true (neoplastic) polyps in 0.60 percent, with size the main predictor (Elmasry 2016); Cancer Research UK summarises that about 8 percent of polyps of 10 mm or more are malignant and about 4 percent of polyps are that size. The 2022 joint guideline of ESGAR, EAES, EFISDS and ESGE sets the rules: ultrasound as the primary test; cholecystectomy for polyps of 10 mm or more, for symptomatic polyps with no other cause, and for 6 to 9 mm polyps with a risk factor (age over 60, primary sclerosing cholangitis, Asian ethnicity, or a sessile polyp including focal wall thickening over 4 mm); ultrasound follow-up at 6 months, 1 and 2 years for 6 to 9 mm polyps without risk factors and for polyps of 5 mm or less with a risk factor, stopping at 2 years if there is no growth; no follow-up for polyps of 5 mm or less without risk factors; surgery if a polyp reaches 10 mm, discussion if it grows 2 mm or more; and an end to monitoring if it disappears (Foley 2022). In primary sclerosing cholangitis polyps were found in 16 percent of 453 patients and most were benign, with cancer associated with size over 10 mm, growth or a mass-like appearance (van Erp 2020). The mass-forming preinvasive neoplasm of 1 cm or more is the intracholecystic papillary neoplasm (Adsay 2012).