Gallbladder polyp found by chance: follow-up scans
Gallbladder polyps are a common finding on an ultrasound of the abdomen done for another reason. SRU says most polyps under 10 mm are benign cholesterol polyps with no built-in cancer risk. (SRU 2022) This page covers which polyps get repeat scans, how often and for how long, not surgery or treatment.
The main guidance
- ESGAR/EAES/EFISDS/ESGE 2022: joint European guideline from radiology, surgery and endoscopy societies, updating their 2017 version. (ESGAR 2022)
- SRU 2022 (Society of Radiologists in Ultrasound): consensus recommendations for polyps found by chance on ultrasound. (SRU 2022)
- KSAR 2025 (Korean Society of Abdominal Radiology): recommendations on reporting and follow-up, with a table comparing other guidelines. (KSAR 2025)
- ACR 2013 white paper (American College of Radiology): gallbladder and biliary findings seen by chance on CT and MRI. (ACR 2013)
- CAR (Canadian Association of Radiologists): 2020 recommendations, updated in 2025 to follow the SRU approach rather than the more cautious European one. (CAR 2025 update)
Who it applies to
These schedules are for polyps found by chance in people with no symptoms. KSAR says its schedule does not apply to people with symptoms, primary sclerosing cholangitis (PSC) or a raised CA 19-9 blood level; for them the follow-up is set one by one. (KSAR 2025) ESGAR says monitoring is for people who could have surgery if it were needed. (ESGAR 2022)
Which test
Ultrasound of the abdomen is the main test for finding and following polyps. ESGAR does not recommend other scans routinely, though contrast or endoscopic ultrasound may help in hard cases at expert centres. (ESGAR 2022) KSAR does not recommend routine CT or MRI, and says a polyp under 6 mm seen on CT or MRI needs no more tests, while one of 6 to 9 mm gets an ultrasound in 6 months. (KSAR 2025)
Risk factors
- ESGAR 2022: age over 60, PSC, Asian ethnicity, and a sessile (flat-based) polyp, including focal gallbladder wall thickening over 4 mm. ESGAR says its 2017 version named Indian ethnicity, and it widened this to all Asian groups based on a review of 43 studies. (ESGAR 2022)
- CAR 2020: age over 50, a sessile or single polyp, PSC and Indian ethnicity. (KSAR 2025)
- KSAR 2025: calls older age, Asian ethnicity and PSC known risk factors for gallbladder cancer, but bases its schedule on size, age 50 and "concerning features": wall thickening next to the polyp, a sessile shape, or significant growth. (KSAR 2025)
- SRU 2022: sorts polyps by their shape into extremely low, low and indeterminate risk. (KSAR 2025)(CAR 2025 update)
Size bands and how often
| Guidance | No follow-up | Follow-up ultrasound |
|---|---|---|
| ESGAR 2022 | 5 mm or less with no risk factors | 6 to 9 mm with no risk factors, or 5 mm or less with risk factors: at 6 months, 1 year and 2 years |
| KSAR 2025 | Under 6 mm with no concerning features | 6 to 9 mm, under 50, no concerning features: yearly for 5 years. 6 to 9 mm with concerning features under 50, or aged 50 or over without them: every 6 months for the first year, then yearly for 4 years |
| SRU 2022 | Depends on shape and size | Low risk 7 to 9 mm: once at 12 months. Extremely low risk 10 to 14 mm: at 6, 12 and 24 months |
| CAR 2020 | Under 7 mm (ACR 2013 also) | 7 to 9 mm with no risk factors: yearly. With risk factors: every 6 months for the first year, then yearly |
Sources for the table: the ESGAR main recommendations; KSAR statements S16 and S17; the KSAR comparison table for SRU and CAR 2020; and the ESGAR text for the ACR and CAR under 7 mm rule. (ESGAR 2022)(KSAR 2025) Larger polyps, 10 mm or more in ESGAR or 15 mm or more in SRU and KSAR, move beyond follow-up scans to a surgical opinion. (ESGAR 2022)(KSAR 2025)
When follow-up stops
- ESGAR: after 2 years with no growth, or sooner if the polyp disappears. (ESGAR 2022)
- KSAR: stopping can be considered when a 6 to 9 mm polyp has been stable for 5 years. (KSAR 2025)
- SRU: 1 year of follow-up or less for most small polyps, depending on shape. (Seguin 2023)
- CAR 2020: follow-up for up to 5 years. (Seguin 2023)
ESGAR cites a large US cohort followed for up to 20 years in which gallbladder cancer was as common in people with polyps as in people without them (0.053% vs 0.054%), and whose authors suggested one or two follow-up scans over 1 to 2 years. (ESGAR 2022)
Growth that changes the plan
- ESGAR: growth of 2 mm or more within the 2 years of follow-up leads to a review of the current size and risk factors, which may be a team discussion; growth to 10 mm leads to a surgical opinion. ESGAR also notes that slow growth is part of how polyps normally behave. (ESGAR 2022)
- KSAR: significant growth means moving from under 10 mm to 10 mm or more, from 10 to 14 mm to 15 mm or more, or a clear increase since the last scan; then the plan is looked at again. (KSAR 2025)
- SRU: defines rapid growth as an increase of 4 mm or more in a year. (KSAR 2025)
Routine age-based screening
A polyp found by chance does not replace the routine screenings for your age. For other findings on a scan, see pancreatic cyst found by chance, kidney cyst found by chance, adrenal mass found by chance, ovarian cyst found by chance and lung nodule found by chance.
Where they differ:
- Smallest size followed. ESGAR follows polyps over 5 mm, KSAR from 6 mm, and ACR and CAR from 7 mm. (ESGAR 2022)(KSAR 2025)
- How long. SRU 1 year or less for most small polyps, ESGAR 2 years, KSAR and CAR 2020 up to 5 years. (Seguin 2023)(ESGAR 2022)(KSAR 2025)
- Age. ESGAR uses over 60 as a risk factor; CAR 2020 uses over 50 and KSAR uses 50 to set how often. (ESGAR 2022)(KSAR 2025)
- Ethnicity. ESGAR 2022 counts all Asian groups; CAR 2020 names Indian ethnicity; KSAR does not change its report for these factors. (ESGAR 2022)(KSAR 2025)
- Growth. ESGAR reviews growth of 2 mm or more in 2 years; SRU uses 4 mm or more in a year; KSAR uses a change of size band or a clear increase. (ESGAR 2022)(KSAR 2025)
- Overall approach. The 2025 CAR update chose the SRU approach, with less follow-up for small polyps, over the more cautious European guideline. (CAR 2025 update)
Your doctor decides what your result means for you.
Questions people ask
Are most gallbladder polyps cancer?
No. SRU says the vast majority of polyps under 10 mm are benign cholesterol polyps, and recent studies found the overall risk of gallbladder cancer is not higher in people with small polyps. (SRU 2022)
Does a small polyp need follow-up?
Often not. ESGAR lists no follow-up for a polyp of 5 mm or less with no risk factors, KSAR for one under 6 mm with no concerning features, and ACR and CAR for one under 7 mm. (ESGAR 2022) (KSAR 2025)
Which test is used?
Ultrasound of the abdomen. ESGAR and KSAR both say other scans such as CT or MRI are not used routinely. (ESGAR 2022) (KSAR 2025)
How long does follow-up last?
It depends on the body: SRU 1 year or less for most small polyps, ESGAR 2 years, and KSAR and CAR 2020 up to 5 years. (Seguin 2023) (ESGAR 2022) (KSAR 2025)
What if the polyp disappears?
ESGAR says monitoring can stop if the polyp disappears during follow-up. (ESGAR 2022)
Related
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- Fatty liver seen by chance on a scan
- Diverticulosis found by chance and colon screening
- Spleen lesion found by chance: follow-up scans
- Liver lesion found by chance: follow-up scans
- Pancreatic cyst found by chance: follow-up scans
- Kidney cyst found by chance: Bosniak follow-up
- Adrenal mass found by chance: follow-up tests
- Ovarian cyst found by chance: follow-up scans
- Lung nodule found by chance: follow-up scans
- After an abnormal screening result
- False positives and overdiagnosis
- Screenings by age and gender