Management of a 0.6 cm Asymptomatic Gallbladder Polyp
No further intervention is required for this 35-year-old woman with an incidental 0.6 cm (6 mm) gallbladder polyp. 1, 2
Evidence-Based Rationale
The 2022 Society of Radiologists in Ultrasound (SRU) consensus guidelines—the most authoritative and recent guidance on this topic—explicitly state that polyps ≤6 mm require no follow-up imaging in patients without risk factors for malignancy. 1, 2 This recommendation is supported by robust population-level data showing:
- Zero documented cases of malignancy in polyps <10 mm at initial detection across approximately 3 million gallbladder ultrasounds 2
- Cancer rates of only 1.3 per 100,000 patients for polyps <6 mm 3
- 0% malignancy rate specifically for polyps <5 mm 2, 3
The 2022 European multisociety guidelines (ESGAR/EAES/EFISDS/ESGE) similarly recommend no follow-up for polyps ≤5 mm without risk factors, and only surveillance (not surgery) for 6-9 mm polyps without risk factors. 4
Risk Stratification for This Patient
This patient has no identifiable risk factors that would alter management:
- Age <60 years (she is 35) 4
- No primary sclerosing cholangitis 4
- No Asian ethnicity mentioned 4
- Asymptomatic (no biliary symptoms) 4
- No gallstones (explicitly stated as absent) 4
The polyp morphology (sessile vs. pedunculated) would only matter if it were larger—pedunculated "ball-on-the-wall" polyps require no follow-up if ≤9 mm, while sessile polyps require no follow-up if ≤6 mm. 1, 2 At 6 mm, this polyp falls below both thresholds regardless of shape. 1
Why Other Options Are Incorrect
Surgical consultation (Option A) is inappropriate because cholecystectomy is recommended only for polyps ≥10 mm or those with concerning features. 1, 4 Operating on a 6 mm polyp would expose this patient to unnecessary surgical morbidity (2-8%) and mortality (0.2-0.7%) without benefit. 2
Liver function tests (Option C) are not indicated for incidental, asymptomatic gallbladder polyps and are not included in any guideline-recommended evaluation pathway. 2 The bile ducts are already documented as normal on ultrasound. 2
Follow-up ultrasound within 6 months (Option D) represents overdiagnosis and unnecessary healthcare utilization. 5 The SRU guidelines reserve surveillance for polyps 7-9 mm (with 12-month initial follow-up for low-risk morphology) or 10-14 mm (with 6-month initial follow-up). 1 Extended surveillance beyond what is indicated wastes resources without improving outcomes. 5
Critical Pitfalls to Avoid
Do not confuse tumefactive sludge with true polyps: Sludge is mobile and layering, while true polyps are fixed and non-mobile. 2, 5 If there is any diagnostic uncertainty, a repeat fasting ultrasound can clarify the finding. 2
Recognize that size fluctuations of 2-3 mm are part of natural history: Nearly half of polyps increase or decrease in size over time without clinical significance. 1, 5 Minor fluctuations should not trigger intervention if future imaging is performed for other reasons. 5
Future imaging is warranted only if: The patient develops right upper quadrant pain or biliary colic symptoms 5, or if incidental imaging for other reasons shows the polyp has grown to ≥10 mm 5