What is a gallbladder polyp?
Gallbladder polyp is an abnormal growth that protrudes from the inner surface of the gallbladder into its lumen. In about 5% of the cases, the polyps become cancerous .
Types of Gallbladder Polyps
Gallbladder polyps can be benign or malign :
- Benign polyps:
- Cholesterol polyps (most common, usually <10 mm, commonly multiple, with a stalk, do not develop into cancer)
- Inflammatory polyps (<10 mm, do not develop into cancer)
- Epithelial tumors: adenomas (5-20 mm, usually solitary and accompanied with gallstones, can develop into a cancer)
- Adenomyomatosis – a benign noninflammatory lesion that can develop into a cancer
- Mesenchymatous tumors: fibroma, lipoma, and hemangioma, leiomyoma, granular cell tumor
- Malign polyps:
- Mucinous cystadenoma
- Squamous cell carcinoma
Risk Factors For Polyps
- Age >60
- Female sex
- Primary sclerosing cholangitis
- Chronic hepatitis B
- Congenital Peutz-Jeghers and Gardner syndrome
- Reference: 
In most cases, gallbladder polyps do not cause any symptoms, but sometimes they can cause:
- Pain in the right upper abdominal quadrant
- Nausea, vomiting
Polyps are often associated with gallstones .
Rare complications include acute acalculous cholecystitis, obstructive jaundice and cancer. Cholesterol polyps can detach, lodge in the common bile duct and cause pancreatitis .
Gallbladder polyps greater than 5 mm can be detected by an ultrasound of the abdomen. An ultrasound can reveal the number and size of the polyps and distinguish between a cholesterol polyp and adenoma but cannot reliably distinguish between a benign and malign polyp .
Picture 1. An ultrasound image (sonogram)
of a 2 cm gallbladder polyp
(source: Ultrasoundcases, by permission)
Endoscopic ultrasound (EUS) and high-resolution ultrasound (HRUS) seem to be equally effective in differentiating benign and malign polyps .
Computerized tomography (CT), magnetic resonance imaging (MRI) and intravenous cholecystography are less sensitive in detective gallbladder polyps than an ultrasound .
Risk Factors For Development Into a Cancer
- Age >50
- Diabetes mellitus
- Gallstones or biliary sludge
- Primary sclerosing cholangitis
- Chronic infection with Salmonella typhi
- Porcelain gallbladder (calcification of the gallbladder wall)
- Polyp size >1.5 cm (but any polyp >6 mm is an indication for a gallbladder removal)
- Single polyp
- Sessile polyp (without a stalk)
- Symptomatic polyp
- References: [1,2]
A doctor will likely suggest gallbladder removal (cholecystectomy) when :
- Cholesterol polyps and other polyps with low cancerous potential are greater than 10 mm
- Adenomas and other polyps greater than 6 mm are associated with increased risk for cancer
- Polyps of any size are associated with primary sclerosing cholangitis
A surgical technique of choice for the removal of the gallbladder with polyps is laparoscopic cholecystectomy . In polyps larger than 18 mm, which are commonly cancerous, an open surgery with gallbladder, partial liver and regional lymph node removal is indicated .
Small polyps that are not removed should be followed up in regular intervals, for example, every 6 to 12 months .
There is no specific diet that would prevent gallbladder polyps. Since gallbladder polyps are commonly associated with gallstones, the diet that can help prevent gallstones may also reduce the risk of gallbladder polyps [3,4]. Main points:
- Maintain healthy body weight.
- Do not skip meals.
- If you intend to lose weight, do it slowly.
- Consume less saturated fats (red meat, cheese) and cholesterol (eggs, shrimps).
- Sandberg AA, 2012, Diagnosis and Management of Gallbladder Polyps PubMed Central
- VanderMeer TJ, Gallbladder tumors, overview Emedicine
- Gallstones prevention Mayo Clinic
- Dieting and gallstones National Institute of Diabetes and Digestive and Kidney Diseases