Pigment vs. cholesterol microlithiasis: comparison of clinical features, bacteriology, stone and gallbladder composition.

We compared 16 cases of pigment microlithiasis with 12 cases of cholesterol microlithiasis. In each case we made a spectrophotometric and diffractometric analysis of the composition of the stones, also analysing bile bacteriology, bile lipid composition and cholesterol saturation indices. The two groups were comparable as regards sex, age, symptoms and clinical features. Pigment microcalculi were often asymptomatic (41.7%), but more often associated with bile bacteria (43.7%) or acute pancreatitis (25%). The results were such as to permit us to view cholesterol microlithiasis and pigment microlithiasis as having different pathogenetic and clinical aspects, and thus as being different diseases.