What to know about gallbladder polyps

A polyp is an abnormal growth of tissue. Some polyps are small, flat bumps, while others hang from tiny stalks.

Polyps can form in various parts of the body, including the gallbladder. Researchers estimate that gallbladder polyps affect 0.3–9.5% of the population.

There are three main types of gallbladder polyps: pseudopolyps, inflammatory polyps, and true gallbladder polyps.

Pseudopolyps

Pseudopolyps, also known as cholesterol polyps, are the most common type, accounting for 60–90% of all gallbladder polyps. Pseudopolyps are noncancerous, cholesterol-filled growths.

Their presence sometimes indicates an underlying gallbladder issue, such as chronic cholecystitis. This is the term for gallbladder inflammation, which occurs when the gallbladder does not empty sufficiently.

Inflammatory polyps

Inflammatory polyps account for 5–10% of all gallbladder polyps. They indicate inflammation in the wall of the gallbladder.

Doctors usually find inflammatory polyps in people who have experienced cholecystitis more than once and those who have acute biliary colic. Biliary colic can occur when a gallstone blocks the duct of the gallbladder, and it typically results in pain after eating.

Inflammatory polyps are not associated with gallbladder cancer.

True gallbladder polyps

True gallbladder polyps are rare and have the potential to become cancerous.

These polyps typically measure 5–20 millimeters (mm) in diameter. Any that are larger than 1 cm are more likely to become cancerous.

When a person has larger polyps, the doctor may recommend removing the gallbladder.

Gallbladder polyps do not always cause symptoms. In many cases, doctors find them unexpectedly on ultrasound or CT scans.

However, gallbladder polyps can sometimes cause the following symptoms:

• discomfort in the upper right side of the abdomen
• bloating
• nausea
• food intolerances

People with high levels of cholesterol or salts in their bile have an increased risk of developing gallbladder polyps. The liver produces bile and stores it in the gallbladder. The gallbladder’s main function is to help the body digest fat.

Gallbladder polyps are also associated with the formation of gallstones. Many people have both gallbladder polyps and gallstones.

The following health issues may increase a person’s risk of developing true gallbladder polyps:

• familial polyposis, an inherited condition
• Gardner syndrome, a type of familial polyposis
• Peutz-Jeghers syndrome, a genetic condition
• hepatitis B, a viral infection that can be acute or chronic

The majority of gallbladder polyps are pseudopolyps or inflammatory polyps. These do not cause complications and are not associated with cancer.

However, doctors regularly monitor all gallbladder polyps, regardless of their type. Removal of the gallbladder is only necessary if people experience symptoms or a polyp grows larger than 1 cm. The most significant complication of true gallbladder polyps is gallbladder cancer.

The biopsy procedure that doctors sometimes use to confirm the diagnosis can also potentially cause complications. These include bleeding, infection, and the leaking of bile.

Only true gallbladder polyps are associated with cancer. The stages of gallbladder cancer range from 0 to 5, with stage 5 being the most advanced.

The 5-year survival rate for stage 1 gallbladder cancer is less than 50%.

Doctors detect fewer than 10% of gallbladder cancer cases when they are at stage 0 or 1. They diagnose the majority of cancerous gallbladder polyps at a more advanced stage.

Factors that can increase a person’s risk of developing gallbladder cancer include:

• being over 50 years of age
• being of Indian ethnicity
• having a history of primary sclerosing cholangitis
• having a flat, or sessile, polyp, along with thickening of the gallbladder wall

Meanwhile, research indicates that people with pseudopolyps or inflammatory gallbladder polyps have almost no risk of developing gallbladder cancer.

Nonetheless, doctors monitor all gallbladder polyps closely. Those that grow larger than 1 cm have a higher likelihood of becoming cancerous. When a person has a polyp of this size, the doctor will advise removing the gallbladder.

Pseudopolyps and inflammatory polyps that are smaller than 1 cm and do not cause symptoms do not require treatment.

However, doctors routinely monitor all gallbladder polyps using ultrasound scans. The first scan usually takes place 6 months after the initial discovery of the polyp. Subsequent scans tend to occur at yearly intervals.

If a polyp has grown by 2 mm or more since the last checkup, the doctor will recommend the surgical removal of the gallbladder, which is called a cholecystectomy. There are two types: open cholecystectomy and laparoscopic cholecystectomy.

An open cholecystectomy involves the surgeon removing the gallbladder via a large incision under the right side of the rib cage. During a laparoscopic cholecystectomy, they will instead remove the gallbladder via small incisions in the abdomen.

Although gallbladder surgery typically has good outcomes, some possible complications include:

• bile duct injuries
• internal or external bleeding
• abscesses under the liver

Currently, the only treatment option for gallbladder polyps is the surgical removal of the gallbladder. However, as people with high cholesterol have an increased risk of developing cholesterol polyps, lowering cholesterol levels in the blood may help prevent cholesterol polyps from forming in the first place.

The American College of Cardiology and similar institutions recommend dietary changes for people with high cholesterol.

A low cholesterol diet includes plenty of the following foods:

• vegetables
• fruits
• whole grains
• legumes
• low fat dairy
• low fat poultry
• fish
• seafood
• nontropical vegetable oils

People with high cholesterol should also limit their intake of:

• sweets
• sugar-sweetened beverages
• red meats

Another way to lower cholesterol is through exercise. People should aim to exercise for a minimum of 40 minutes at least three times a week. The exercise should be aerobic and moderate to vigorous in intensity.

Some people may also need to take medication that lowers their cholesterol.

People with gallbladder polyps may not experience symptoms. Most gallbladder polyps are noncancerous, but they still require regular monitoring.

Surgery is necessary if polyps cause symptoms or are larger than 1 cm. Doctors also recommend surgery when a polyp has grown by 2 mm or more since the person’s last checkup.

True gallbladder polyps are rare, but they can cause gallbladder cancer. The standard treatment is the surgical removal of the gallbladder. Survival rates for people with this type of cancer are higher when doctors detect the cancer at an early stage.