18 F-FDG PET/CT in the Evaluation of Polyarteritis Nodosa.

A 61-year-old man with a medical history of human immunodeficiency virus well controlled on antiretroviral therapy presented for distal sensorimotor symptoms, fatigue, and recurrent fevers. Erythrocyte sedimentation rate and C-reactive protein were both elevated. Antineutrophilic cytoplasmic antibody and antinuclear antibodies were negative. Neurologic imaging workup was unremarkable. 18 F-FDG PET/CT, which was crucial for diagnosis, demonstrated pathological tracer activity throughout the medium-sized vessels with sparing of the aorta. In view of presentation, comorbidities, and imaging findings, polyarteritis nodosa was diagnosed. The patient was treated appropriately with steroids and cyclophosphamide with significant symptomatic improvement.