Chronic cholecystitis with hilar bile duct stricture mimicking gallbladder carcinoma on positron emission tomography: A case report.

Thickening of the gallbladder wall is observed in patients with gallbladder carcinoma, as well as in those with chronic cholecystitis. It is difficult to distinguish between benign and malignant gallbladder wall thickening with conventional diagnostic imaging techniques, such as abdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI), particularly in patients with bile duct strictures. Currently, the fluorine-18 2-fluorodeoxyglucose positron emission tomography/CT (F-18 FDG PET/CT) scan is widely used in the differentiation of cholecystitis from gallbladder carcinoma. However, the F-18 FDG PET/CT scan may also be responsible for false-positive diagnosis. This case report focuses on a 74-year-old male who presented with thickening of the gallbladder wall and hilar bile duct stricture, originally misdiagnosed as gallbladder carcinoma by US and MRI. F-18 FDG PET/CT also demonstrated increased activity. This case was ultimately proven to be chronic cholecystitis by postoperative pathological examination and it is presented in order to emphasize the significance of considering the possibility of false-positive diagnosis by PET/CT, as a result of inflammatory lesions. Therefore, PET/CT should not be considered the gold standard for the discrimination between benign and malignant gallbladder wall thickening.