Image Description: In the wall of the gallbladder, subepithelial and subserosal fibrosis are present. The Rokitansky-Aschoff sinuses are prominent (glandular structures deep in the wall). Note the flat atrophic mucosa (top of image). The normally tall columnar epithelium of the mucosa is flat; the normal epithelial folds are gone. There is muscle hypertrophy (thicker pink-red bands below the mucosa); the latter is consistent with cystic duct obstruction.