Dual-time-point PET/CT to differentiate fluorodeoxyglucose-avid hiatal hernia from mediastinal malignancy

It has been reported that a hiatal hernia may accumulate F-18 fluorodeoxyglucose (FDG) and such a focal F-18 FDG activity detected in the middle-posterior mediastinum usually raises the unnecessary suspicion of malignancy. The F-18 FDG uptake might be the result of physiological gastric activity or an inflammatory process associated with gastroesophageal reflux in a hiatal hernia patient. For the suspected esophageal hiatal lesion, diminished F-18 FDG activity on delayed imaging and identification of gastrointestinal loops by coregistered computed tomography could assist with the diagnosis of a hiatal hernia. We describe a case of hiatal hernia featuring a paraesophageal mass with disappearing F-18 FDG avidity in the middle-posterior mediastinum during a PET scan for cancer workup.