Benign Cutaneous and Subcutaneous Lesions on FDG-PET/CT

18F-FDG, the most commonly used PET radiopharmaceutical in clinical practice, can also accumulate in inflammatory and infectious conditions. This may account for false-positive PET findings when staging or restaging a patient with malignancy. As clinical use of FDG-PET-CT is increasing, nuclear medicine physicians are encountering a myriad of cutaneous and subcutaneous lesions, many of which are incidental and benign. The most common cause for the FDG avidity of these lesions is inflammation. Although a specific diagnosis may not always be possible, background clinical history and morphologic features of the lesion on CT may help narrow the differential diagnosis. This article aims to familiarize nuclear medicine physicians and radiologists with various benign cutaneous and subcutaneous conditions encountered in routine clinical practice.