PET/CT is an established modality for evaluation of malignant disease. However, in many cases, specificity is impaired by false-positive findings. Recognition of these cases is crucial for correct diagnosis and subsequent patient management. In the presented case, malignant disease was suspected in a young man because of a history of B symptoms. F-FDG PET/CT showed hypermetabolic foci in both inguinal regions initially classified as possible lymphoma. Using a novel technique for PET/US fusion, ultrasound and PET were coregistered to clarify that PET hypermetabolism was due to a foreign body reaction after plug hernioplasty performed several years earlier.