Fig. 1
From: Gallbladder adenomyomatosis: imaging findings, tricks and pitfalls
Gallbladder adenomyomatosis: pathology findings. Macroscopically (a) GA is characterized by gallbladder wall thickening (lines) containing small cystic spaces (arrows) representing Rokitansky–Aschoff sinuses. Microscopically, at low (2×) magnification (b and c), wall thickening is due to hyperplasia of the muscular layer (lines); a variable degree of epithelial proliferation (arrowheads) is also appreciable and epithelium-lined cystic spaces, representing RAS (arrows), can be observed within the muscular layer. Biliary stones (star) may be present within RAS. At high (40×) magnification (d), the proliferative mucosal glandular component that leads to epithelial infolding (arrowheads) and RAS formation is better recognizable