ULTRASTRUCTURAL ASPECTS OF HUMAN CYSTIC DUCT EPITHELIUM AS A RESULT OF CHOLELITHIASIS AND CHOLESTEROLOSIS

Although there is a large body of data on the gallbladder and the impo rtance of the cystic duct in surgical procedures, there is insufficien t data regarding the morphology of the human cystic duct. In the prese nt study, transmission electron microscopic (TEM) and scanning electro n microscopic (SEM) survey of several surgical and autopsy cystic duct s in cholelithiasis and cholesterolosis is reported. In cholelithiasis , similar to gallbladder epithelium, the cystic duct epithelial cells display minor-to-severe alterations of the epithelial surface accompan ied by variable erosion of the epithelium. Areas of intact surface epi thelium demonstrate microvilli-covered cells coated by a rich glycocal yx and mucous production. In other areas, apical excrescences are asso ciated with mucus hyperproduction and secretory events. Lipoid bodies are also present in many cells and especially in many of the cells' su bluminal apical areas. In cholesterolosis, mucous secretory granules a ppear dilated, fatty deposits are infrequent, and peculiar intracellul ar cholesterol deposits can be detected in the apical and subapical re gion of cells and around condensed mitochondria. Following elective ch olecystectomies, predominantly in association with cholelithiasis, ero ded areas were detected; therefore, it appears that the action of intr aluminal calculi may be a principal causative factor in discrete epith elial erosions of the cystic duct. Intraluminal calculi/debris, along with the alteration of mucus, cell sloughing, and a decreased pool of bile acids and motility may participate in the gallstone nucleation pr ocess. The peculiar cholesterol inclusions may also play a role in tha t nucleating process. (C) 1997 Wiley-Liss, Inc.