Paper II
Question
Name the types of gall bladder calculi
Answer
Gallbladder (gallstone) calculi are of three types:
- Cholesterol stones — pale yellow, composed predominantly (>50%) of cholesterol monohydrate crystals.
- Pigment stones — small, dark, composed predominantly of bilirubin (calcium bilirubinate); subdivided into black pigment stones (associated with haemolysis/cirrhosis) and brown pigment stones (associated with biliary tract infection/infestation).
- Mixed stones — the most common type in practice, containing varying proportions of cholesterol, bile pigment, and calcium salts, often laminated.

