Ruptured epidermal cyst mimicking cutaneous melanoma on F-18 FDG PET/CT.

F-18 FDG PET/CT provides an accurate staging and post-therapeutic evaluation of melanoma based on high metabolic characteristics of its primary and secondary lesions. This functional imaging modality may, however, detect coexisting benign lesions of inflammatory or infectious origin mimicking malignancy thus interfering with the staging of cancer. The authors present a case of ruptured epidermal inclusion cyst exhibiting abnormal radiotracer accumulation on PET/CT in a patient with a history of recurrent metastatic melanoma.