An electron microscopic study of intestinal metaplasia in human gallbladder

Areas of intestinal metaplastic epithelium in gallbladders removed by cholecystectomies performed for gallstones were studied with the electron microscope. Three gallbladders contained areas of goblet cells and endocrine enterochromaffin-like cells and one gallbladder also Paneth cells. The goblet cells contained mucin granules of slightly variable size and shape and relatively great electron lucency. The intervening columnar epithelial cells contained various amounts of electron-lucent mucin granules. The round or oval enterochromaffin-like cells rested on the basement membrane, and in these cells the small, round, electron-opaque secretory granules were located in the infranuclear region. The supranuclear cytoplasm of the Paneth cells in the intestinalized epithelium contained typical large, round secretory granules. The fine structures of the various cells in the metaplastic epithelium bore resemblance to those of the cells in the intestinalized stomach mucosa.