Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography-Positive Ear Lesions Responsive to Immunosuppressive Therapy in a Patient with Otitis Media with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

A 74-year-old woman presented with vertigo, left beating nystagmus, and auditory disturbance 4 months prior, in whom a former physician suspected Meniere's disease. Her signs and symptoms mildly improved with a moderate dose of glucocorticoids, which was eventually tapered. Fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) was performed 12 days prior to routine examination. Remarkable FDG uptake was observed in the surrounding areas of the bilateral Eustachian tubes and left middle ear, which was only partially detected on magnetic resonance imaging. The patient also tested positive for myeloperoxidase-antineutrophil cytoplasmic antibody (ANCA). She was admitted to our hospital and diagnosed with otitis media with ANCA-associated vasculitis (OMAAV) based on the classification criteria. Four months after immunosuppressive therapy, the abnormal ear findings were not observed on follow-up FDG-PET/CT. The clinical course of this case suggests that FDG-PET/CT can detect occult ear involvement better than do other modalities in patients with OMAAV. In addition, FDG-PET/CT-positive ear lesions responded to immunosuppressive therapy. Therefore, FDG-PET/CT can help distinguish OMAAV from other ear diseases with non-inflammatory aetiologies and detect occult treatment-responsive OMAAV lesions in the clinical setting.