[Crystal morphology of cholesterol monohydrate in cholesterol gallstones and gallbladder bile]

To understand the pathogenesis of cholesterol gallstones from a crystallographic point of view, we investigated gallstones and precipitates in gallbladder bile by the optical method used in crystallography. First, ground thin sections of cholesterol gallstones in 28 cases were examined by a polarizing microscope. The crystalline fragments which were peeled off from gallstones by sonication were also examined in the same manner. Secondly, the cholesterol monohydrate crystals in gallbladder bile were examined by a polarizing and phase contrast microscope. The bile samples were obtained from 15 patients with cholesterol gallstones by the needle puncture of gallbladder during surgery. The results of observation were as follows. 1) The cholesterol gallstones were composed of many small plated cholesterol monohydrate crystals aggregated radially. 2) Each small plated crystal was grown by the lateral growth mechanism in bile. Spiral growth patterns were often observed on the (001) faces. 3) The cholesterol gallstones were formed by two successive mechanisms: The aggregation of cholesterol monohydrate crystals and the lateral growth of each single crystal.