The gallbladder: uncommon gallbladder conditions and unusual presentations of the common gallbladder pathological processes.

This article reviews a spectrum of gallbladder conditions that are either uncommon or represent unusual manifestations of common diseases. These conditions are divided into four major categories: (a) congenital anomalies and normal variants including duplication, ectopia, and lymphangioma; (b) inflammatory processes and stone-related diseases and complications including adenomyomatosis, emphysematous cholecystitis, xanthogranulomatous cholecystitis, gangrenous and hemorrhagic cholecystitis, perforation, gallstone ileus, and Bouveret and Mirizzi syndromes; (c) gallbladder neoplasms including adenocarcinoma with associated porcelain gallbladder, squamous cell carcinoma, lymphoma, melanoma, and neurofibroma. A thorough understanding of the imaging characteristics of each condition can help the radiologist to make a timely and accurate diagnosis, thus avoiding potentially harmful delays in patient management and decreasing morbidity and mortality rates.