Gallbladder polyps
Gallbladder polyps are projections from the gallbladder lining, found on around 5% of ultrasound scans. The overwhelming majority are entirely harmless and require nothing. A small minority are, or may become, gallbladder cancer. Because gallbladder cancer has a poor outlook when found late, the purpose of assessment is to identify that minority without removing hundreds of normal gallbladders in the process.
How they form
"Polyp" describes an appearance on ultrasound, not a diagnosis. Several quite different things produce it:
- Cholesterol polyps — by far the commonest, accounting for the majority. They are not tumours at all. Cholesterol from supersaturated bile is taken up by macrophages in the gallbladder wall, which accumulate beneath the lining and form small yellow projections. They are typically multiple, small, and attached by a thin stalk. They have no malignant potential whatsoever.
- Inflammatory polyps — granulation tissue arising from chronic inflammation, usually in a gallbladder that also contains stones. Benign.
- Adenomyomatosis — overgrowth of the gallbladder lining with outpouchings into the muscular wall (Rokitansky–Aschoff sinuses). It produces a characteristic appearance and is benign.
- Adenomas — true benign tumours of the lining. They are uncommon but important, because like adenomas in the colon they can progress to carcinoma.
- Adenocarcinoma — malignant from the outset, or arising within an adenoma.
The essential problem is that ultrasound cannot reliably distinguish between these. The distinction is made indirectly, using size, growth and associated features as proxies for risk.
Symptoms
Polyps themselves almost never cause symptoms and are virtually always found incidentally. Where a patient with polyps has biliary pain, it is usually because gallstones are also present. This matters: symptoms are an indication for cholecystectomy in their own right, regardless of the polyp.
How the diagnosis is made
Transabdominal ultrasound is the primary test. It measures size, number, and whether the lesion is sessile or on a stalk, and distinguishes a polyp from a stone by the absence of an acoustic shadow and by failure to move when the patient changes position.
Endoscopic ultrasound gives higher resolution and better assessment of wall layers, and is used for lesions where the distinction matters. Contrast-enhanced ultrasound, CT and MRI assist in assessing larger or suspicious lesions and in staging if malignancy is suspected.
Biopsy is not performed percutaneously, because of the risk of seeding if the lesion is malignant.
Which polyps need removing
Current international guidance combines size with risk factors rather than relying on size alone:
- Cholecystectomy is advised for polyps 10mm or larger, for polyps of any size causing biliary symptoms, and for polyps showing definite growth on surveillance — conventionally an increase of 2mm or more.
- Polyps 6–9mm are assessed for risk factors: age over 60, sessile (broad-based) morphology including focal wall thickening over 4mm, Indian ethnicity, and primary sclerosing cholangitis. Cholecystectomy is advised where a risk factor is present; otherwise surveillance.
- Polyps 5mm or smaller without risk factors are followed with ultrasound, with surveillance typically discontinued after a period of stability.
These thresholds are a framework rather than a rule. A 9mm sessile polyp in a fit 45-year-old with coexisting gallstones and a 9mm stalked polyp in an 85-year-old with cardiac disease warrant different advice, because the balance between a small cancer risk and the risks of an operation falls differently. The recommendation is made for the individual.
One qualification worth understanding: polyps in patients with primary sclerosing cholangitis carry a substantially higher risk of malignancy, and a lower threshold for surgery applies.
Treatment
Laparoscopic cholecystectomy is the treatment. The gallbladder is removed intact and sent for histology; it is not opened during the operation, to avoid spilling cells if a malignancy is present.
Where preoperative assessment raises genuine suspicion of cancer, the approach changes: an open operation, or a laparoscopic operation with careful extraction in a retrieval bag, and consideration of whether a more extensive resection including a rim of liver and regional lymph nodes is required. Incidental gallbladder cancer found on histology after routine cholecystectomy is dealt with on its own page.
Recovery
As for laparoscopic cholecystectomy generally: often a day case or one night, office work within one to two weeks, full activity by about four weeks.
Follow-up
For polyps under surveillance, ultrasound at intervals defined by size and stability. For polyps removed, the histology determines whether anything further is needed — for a cholesterol or inflammatory polyp, nothing at all.
Common questions
Are gallbladder polyps cancer?
Almost always no. The majority are cholesterol polyps, which are deposits of fat in the gallbladder lining and cannot become cancer. The risk relates mainly to size: polyps under 6mm are very rarely malignant, while those of 10mm or more are treated more cautiously.
Do gallbladder polyps need to be removed?
Most do not. Removal is generally advised if a polyp is 10mm or larger, if it is growing, if it causes symptoms, or if it is 6–9mm with additional risk factors. Smaller polyps are usually just monitored with ultrasound.
Do gallbladder polyps cause pain?
Polyps themselves do not usually cause pain. If you have pain and polyps, it is most often because you also have gallstones, or because something else is responsible.
Can a gallbladder polyp disappear?
Some apparent polyps turn out to be sludge or small stones stuck to the wall, and these can disappear between scans. True polyps generally persist.
How often do I need a scan?
This depends on the size of the polyp and whether it has changed. Small stable polyps are typically checked at intervals for a period and then surveillance is stopped. Your surgeon will set the interval for your particular case.
Should I worry while I wait for the next scan?
For a small polyp with no concerning features, the risk of a meaningful change over a surveillance interval is very low. If you develop biliary pain, jaundice or weight loss in the meantime, that is a reason to be reviewed sooner rather than waiting.
Related conditions
Other conditions of the gallbladder & bile ducts covered on this site:
- Gallstones and biliary colic
- Acute cholecystitis
- Common bile duct stones and cholangitis
- Obstructive jaundice
- Gallbladder cancer
- Cholangiocarcinoma (bile duct cancer)
- Bile duct strictures, cysts and benign tumours
- Bile duct injury after gallbladder surgery
This page provides general information and does not replace an individual medical consultation. Assessment and treatment are decided for each patient after review of their history, examination and imaging.