Gallbladder polyps are outgrowths of the internal wall of the gallbladder. They are usually found by accident on ultrasonography or after a gallbladder has removed. The fact that more high quality ultrasound scans are being performed means that polyps in the gallbladder are being found more often.
The vast majority of these lesions are not cancerous but contain normal cells or represent fat deposits (cholesterolosis). Cholecystectomy is sometimes recommended to exclude the possibility of gallbladder carcinoma or pre-cancerous polyps. Sometimes gallbladder polyps can lead to symptoms like those caused by gallbladder stones.
How common are gallbladder polyps?
Gallbladder polyps are found in roughly 3% of people who undergo an ultrasound of their gallbladder
How are gallbladder polyps grouped?
- The most common benign polyp is an adenoma, the risk of an adenoma becoming cancerous relates to the size of the polyp.
- Pseudo-polyps (not really a polyp) are the most common finding which resent cholesterol deposits on the wall cholesterolosis) or adenomyomas (cholesterol deposits in the wall with inflammation)
- The most common cancerous lesion in the gallbladder is adenocarcinoma. Gallbladder adenocarcinomas are much more common than gallbladder adenomas.
What are the symptoms of gallbladder polyps?
Gallbladder polyps most commonly produce no symptoms at all, but the presence of gallbladder like symptoms, with no other explanation is a reason to remove the gallbladder.
What is the risk of cancer in a gallbladder polyp?
The risk of cancer increases with and the size of the polyp. If a polyp is over 1cm it is generally recommended to be removed, to exclude cancerous change.
What tests should be performed?
Ultrasound - modern ultrasound produces excellent images of the gallbladder and can measure the blood flow in a polyp.
CT scan - is performed for large polyps and if gallbladder cancer is suspected.
What is the treatment for gallbladder polyps?
The only effective treatment for gallbladder polyps or cholesterolosis is cholecystectomy, which should be considered in patients with symptoms or to exclude cancerous change in large polyps (this can only be done by examining the gallbladder under a microscope). However very few gallbladder cancers will found in polyps less than 1cm.
For patients with no symptoms the treatment depends on size;
- Large polyps over 2cm require an extended cholecystectomy – sampling lymph nodes and the adjacent liver. This is done as an open procedure.
- Polyps between 1 and 2 cm require a careful cholecystectomy removing all gallbladder tissue. This can be performed as a laparoscopic procedure.
- Polyps small than 1cm can usually be reassessed with an ultrasound scan after 6 months and then every year (if the size remains the same).
- Polyps smaller than 5mm should undergo a single ultrasound at one year (if the size is stable).
For patients with symptoms cholecystectomy is recommended if no other cause for pain is found, but patients should be aware that small polyps are less likely to be the cause of symptoms and as such symptoms may not improve if the gallbladder is removed.