Gall Bladder. There is distention of the gall bladder with abundant luminal accumulations of mucus interspersed with scant amounts of bile. The mucosa of the gall bladder is lined by moderately hyperplastic columnar epithelial cells with accentuation of the normal folds by accumulations of mucus. Within the lamina propria and the tunica muscularis there are occasional multifocal to perivascular accumulations of lymphocytes and rare plasma cells. Hematoxylin and eosin staining. Bar = 250 μm.