[A case of xanthogranulomatous cholecystitis diagnosed by EUS-FNA in which changes were observed on FDG-PET].

An elderly man in his 70s presented with pain in the right hypochondrium. Computed tomography revealed thickening of the gall bladder wall and liver invasion. In addition, fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) revealed an abnormal accumulation in the gall bladder, leading to a suspicion of gall bladder carcinoma. To confirm the diagnosis, endoscopic ultrasound-guided fine-needle aspiration was performed, which revealed a diagnosis of xanthogranulomatous cholecystitis (XGC). FDG-PET revealed decreased wall thickness and standardized uptake value a month later. Cholecystectomy was performed on the basis of a histological and clinical diagnosis of XGC. Histological examination revealed inflammatory and foamy cells and exuberant granulation of the gall bladder wall, confirming XGC.