Positive FDG‐PET/CT uptake guiding diagnosis in a patient with microscopic polyangiitis: A case report

Abstract Microscopic polyangiits (MPA) is an autoimmune vasculitis that is challenging to diagnose because it can present with myriad of manifestations. We present a case of a woman who presented with prolonged fever. Her diagnosis of MPA was realized after fluorine‐18 fluorodeoxyglucose positron emission tomography/computed tomography (F‐18 FDG‐PET/CT) showed abnormal diffuse renal uptake in the cortex, leading to a kidney biopsy. Our report supported the value of FDG‐PET/CT as a diagnostic tool in a patient with febrile illness without localizing symptoms or signs.