[18F]-FDG uptake in soft tissue dermatome prior to herpes zoster eruption: an unusual pitfall.

Authors report on a case of [18F]-fluorodeoxyglucose ([18F]-FDG) uptake in the soft tissue of a patient referred for [18F]-FDG coincidence detection emission tomography (CDET) in a search for recurrence of colorectal cancer. A herpes zoster eruption occurred in the same site within two days, but was spontaneously resolved. To the best of our knowledge this is the first description of a false positive [18F]-FDG result in relation to a viral infection of soft tissue. It shows that interpretation of subcutaneous foci has to be cautious in patients with or without a past history of herpes zoster even in pain-free areas and prior to skin eruption.