Active Herpes Zoster Infection Involving Lumbosacral Dermatome, an Unusual Site of Manifestation and Incidental Finding in Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Scan.

Herpes zoster virus reactivation in the lumbosacral dermatomal distribution is an unusual site of manifestation and atypical in presentation than its usual sites in thoracolumbar (D3-L2) and facial (V1) dermatomes. Here, we are reporting a patient of marginal zone lymphoma who on fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography scan performed for chemotherapy response evaluation showed hypermetabolic cutaneous and subcutaneous lesions in the right vulva and posteromedial aspect of the right thigh along with ipsilateral pelvic lymph nodes involvement as an incidental finding. Subsequently, FDG active lesions were considered to be as herpes zoster virus reactivation rather than the recurrence of lymphoma and treated with antiviral drug.