BACKSCATTERED ELECTRON IMAGING AND ENERGY-DISPERSIVE X-RAY-MICROANALYSIS STUDIES OF EVIDENCE FOR CALCIUM SALT HETEROGENEITY IN 15 GALLSTONES FROM AN ELDERLY HUMAN

We examined 15 variably-sized gallstones, taken from an elderly male, by backscattered electron imaging and energy-dispersive X-ray microana lysis to learn the structural and distribution patterns of gallstone c alcium (Ca-) salts. Of the 13 cholesterol-rich stones, nine stones had peripheral concentric layers of Ca-carbonate, whereas 2 stones had pe ripheral layers of Ca-phosphate. No Ca-salts were detected from 2 chol esterol-rich stones. The 2 stones containing Ca-phosphate had no Ca-sa lt cores, whereas the stones containing Ca-carbonate were separated in to 3 different types: two stones with a Ca-carbonate core, four stones with several Ca-bilirubinate cotes of glass-like structure, and 3 sto nes lacking Ca-salt cores. A closer view of the Ca-salt layers, which may be occasionally coexistent with Ca-bilirubinate, mainly showed eit her laminate deposits or numerous globules with a few laminae. Of the 2 cholesterol-poor stones, one had dispersed particles mainly of Ca-ph osphate, and the other had loosely dispersed particles with small amou nts of Ca-phosphate, bilirubinate, and/or palmitate. Some relationship between the size and Ca-salt species of these gallstones was suggeste d. Gallstones collected from the same individual showed a considerable heterogeneity of Ca-salts.