Other minor risk factors are patients with preexisting chronic cholelithiasis or biliary sludge. These patients need to be further evaluated carefully as the presence of acoustic shadowing from the gallstones during an ultrasound can mask the polyp. Other known pathologies contributing to risk factors are congenital polyposis syndromes, such as Peutz-Jeghers syndrome, Gardner syndrome, and Familial adenomatous polyposis. (3,4) A Chinese retrospective study also found chronic hepatitis B as a risk factor. (3,5)

The majority of the cases are asymptomatic. However, symptomatic patients can present with nausea, vomiting, indigestion, and occasional right upper quadrant pain. The pain can mimic biliary colic but, in this case, it is due to small pieces of detached cholesterol obstructing the neck of the gallbladder. A few reports have presented acalculous cholecystitis and haemobilia. (3,5) The range and severity of symptoms are proportional to the size of the polyp as the larger the polyps, the more they tend to block the flow and cause a higher degree of inflammation.

Ultrasound is the best initial test to diagnose gallbladder polyp as it has good sensitivity, and specificity is easily accessible and has cheaper costs in comparison to other imaging methods. Usually, gallbladder polyps will appear as fixed hyperechoic projecting masses without acoustic shadow; in contrast to gallstones which show acoustic shadow. Cons are that ultrasound cannot distinguish benign from malignant polyps and polyps smaller than 5 mm are not easily caught on imaging. (3,8,9)

Inconclusive ultrasound findings need further testing. Follow-up tests can be done with endoscopic ultrasonography (EUS), CT and PET scans. EUS uses higher ultrasound frequencies and provides a better detailed visual.

A study reported EUS and CT to have an accuracy of 91% in distinguishing benign and malignant polyps on imaging and can be used in patients with risk factors. (3,10)

The surgical treatment of choice is laparoscopic cholecystectomy for benign cases. Open cholecystectomy is the preferred surgical option if the surgeon has imaging evidence of malignant polyps, if the likelihood of gallbladder perforation is high, or if unsure whether imaging is enough to rule out benign polyps. (3,11,12) Open surgery method also provides improved visibility, and easier access to check for regional liver or abdominal metastatic spread, perform lymph node dissection, and prevent intra-abdominal neoplasm diffusion.

The treatment plan (Fig.4) depends on various factors, including patient symptoms, associated conditions, risk factors, and the patient’s choice: (2-4,15)

• Asymptomatic and non-risk patients with polyps that are smaller than 10 mm can be kept on routine abdominal ultrasound or EUS monitoring every 6-12 months for at least 5 years, to check for any sudden growth. Any evidence of further rapid growth of more than 2 mm in size or symptoms needs surgery. Although any patient with a polyp size of more than 6 mm should strongly be advised to consider cholecystectomy for the prevention of complications;

• Symptomatic polyp patients should undergo surgery after appropriate clearance by their surgeon;

• Patients with any of the risk factors mentioned above should have surgery;

• Polyp in patients with primary sclerosing cholangitis or cholecystitis, irrespective of the size, should be referred for operation.