📄

Gallbladder Polyp (SRU 2022)

Guided recommendation from the Society of Radiologists in Ultrasound consensus conference on incidentally detected gallbladder polyps at US (Kamaya et al., Radiology 2022). Answer the questions below.

Applies to an incidentally detected gallbladder polyp on ultrasound — a solid, nonmobile, nonshadowing protrusion from the mucosa, not attributable to a gallstone, sludge, a mucosal fold, or wall thickening. Patient age, sex, coexisting gallstones, polyp number, vascularity, and echogenicity do not alter risk stratification. Size is rounded to the nearest mm.

Encodes the SRU 2022 incidental gallbladder polyp algorithm (Figs 1–2). Recommendations, not standard of care: deviate as the imaging and patient warrant. Surgical decisions require shared decision-making.

Parses size and a few keywords (pedunculated, ball-on-the-wall, sessile, thin/thick stalk, wall thickening) to pre-select below — always review.

Risk categories, thresholds & applicability

Applicability (Fig 1)

Do not apply the SRU algorithm directly if: the study is technically inadequate (short-interval follow-up US in 1–2 months); a >10 mm lesion cannot be distinguished from tumefactive sludge or adenomyomatosis (CEUS or MRI); there is high suspicion for an invasive/malignant tumor — wall invasion, concurrent liver masses, malignant biliary obstruction, or nodal enlargement (refer to oncologic specialist); or the patient has primary sclerosing cholangitis (use AGA/ACG specialty guidelines).

Risk categories by morphology (Fig 2)

Extremely low risk: pedunculated "ball-on-the-wall" or pedunculated with a thin stalk. Low risk: pedunculated with a thick/wide stalk, or sessile (and when shape is uncertain). Indeterminate risk: focal wall thickening ≥4 mm adjacent to the polyp.

Management by size

Extremely low: ≤9 mm no follow-up; 10–14 mm US at 6, 12, 24 months (surgical consult is an acceptable alternative); ≥15 mm surgical consult.

Low: ≤6 mm no follow-up; 7–9 mm US at 12 months; 10–14 mm US at 6, 12, 24, 36 months; ≥15 mm surgical consult.

Indeterminate: ≤6 mm US at 6, 12, 24, 36 months; ≥7 mm surgical consult.

Growth rule (footnote b)

At follow-up, an increase of ≥4 mm within a 12-month period, or reaching the category's surgical threshold (15 mm; 7 mm for indeterminate), warrants surgical consultation. A decrease of ≥4 mm → stop following. Maximum surveillance is 3 years.

Kamaya A, Fung C, Szpakowski JL, et al. Management of Incidentally Detected Gallbladder Polyps: Society of Radiologists in Ultrasound Consensus Conference Recommendations. Radiology 2022;305:277–289. Figures 1 and 2.