What pathology results from plastic changes in the gallbladder wall, leading to wall thickening and diverticula?

Adenomyomatosis is characterized by the presence of hyperplastic changes in the gallbladder wall that result in thickening and the development of diverticula, which are small outpouchings. This condition typically arises from chronic irritation or inflammation of the gallbladder wall. The thickening can be visualized on ultrasound and is often seen as a benign condition without significant clinical implications.

In contrast, cholangitis refers to inflammation of the bile ducts, often due to bacterial infection, while cholecystitis involves inflammation of the gallbladder, commonly from gallstones obstructing the cystic duct. Empyema, on the other hand, is a collection of pus in the gallbladder, which occurs following cholecystitis but does not involve the same plastic changes or diverticula formation seen in adenomyomatosis. Thus, adenomyomatosis is the best match for the question as it describes the specific pathological changes in the gallbladder wall that lead to both thickening and diverticula.