Herpes Zoster on FDG PET/CT: Dermatomal Uptake With Diffuse Splenic Activation.

A 78-year-old woman with endometrial cancer underwent 18 F-FDG PET/CT for treatment response evaluation. Maximum intensity projection and axial images demonstrated diffuse linear hypermetabolic skin thickening along the right thoracic wall, accompanied by hypermetabolic right axillary lymph nodes. In addition, diffuse increased FDG uptake was observed in the spleen. The uptake pattern followed a dermatomal distribution. Clinical evaluation revealed localized pain and vesicular skin eruptions in the same region, consistent with herpes zoster infection.