Increased F-18 FDG uptake on positron emission tomography/computed tomography imaging caused by plantar fibromatosis

We detail the history and evaluation of a 68-year-old man who had head-to-toe PET/CT scanning that showed a focal area of increased FDG uptake in the left medial foot. This was thought to be recurrence of his melanoma. The patient was asymptomatic. He had a history of malignant melanoma of the right ear, which was removed in 2001. On biopsy, the foot lesion was diagnosed as plantar fibromatosis. Plantar fibromatosis is a benign fibroblastic condition, which can be indistinguishable from malignancy in head-to-toe PET/CT scans. Awareness of their potential appearance on PET and PET/CT will aid in the appropriate staging of oncology patients.