Xanthogranulomatous Cholecystitis (XC): It is a rare form of chronic cholecystitis with an incidence of 0.7% to 1.8% in cholecystectomy specimens. In countries like India and Japan, the reported incident is as high as 9%. Macroscopically, gallstones are present in most cases and wall is thickened. Xanthogranulomatous inflammation produces firm, yellow-tan areas that frequently extend into adjacent structures, often resembling gallbladder carcinoma (see also next image). Clinically, the presentation of XC is similar to other forms of cholecystitis. Most patients have experienced one or more bouts of acute cholecystitis characterized by classic "biliary colic." On imaging studies, thickening of the gallbladder wall and adhesions to contiguous structures raises the concern for carcinoma. Image courtesy of: Dr. Ibrahim Zardawi; used with permission.