Rosh Internal Medicine Boost Practice Exam

Which type of gallstone is most commonly found in the United States?

1. Brown pigment

2. Black pigment

3. Calcium carbonate

4. Cholesterol

The correct answer is: Cholesterol

The most commonly found type of gallstone in the United States is cholesterol gallstones. These gallstones are primarily composed of hardened cholesterol and can form when there is too much cholesterol in the bile, an imbalance of bile salts, or other factors that contribute to supersaturation. Cholesterol gallstones are typically yellow-green and vary in size from a few millimeters to several centimeters. Several factors contribute to the prevalence of cholesterol gallstones, including dietary habits, obesity, and certain metabolic conditions. In the U.S., high-fat diets and a sedentary lifestyle are common, leading to an increased risk of cholesterol saturation in the bile. As a result, many individuals develop this type of gallstone, making it the most frequently encountered variant in the country. Other types of gallstones, such as black and brown pigment stones, are less common. Black pigment stones are primarily associated with hemolytic conditions and liver cirrhosis, while brown pigment stones are often linked to infections of the biliary tract or certain conditions affecting the liver. Calcium carbonate stones are not a typical classification of gallstones. Thus, cholesterol gallstones stand out due to their higher incidence in the general population.