RESULTS: Typical FDG uptake was noted in tracheobronchial trees (n=17), nasal cartilage (n = 15), arytenoid cartilage (n = 13), cricoid cartilage (n = 12), auricular cartilage (n = 12), costicartilage (n = 10), thyroid cartilage (n = 8), hyoid cartilage (n = 7) and mediastinum lymph node (n = 2). One patient showed FDG uptake only in cricoid cartilage, another showed no any FDG uptake. PET/CT-guided biopsy were performed in ten patients (three in nasal cartilage, seven in auricular cartilage). Biopsies of auricular cartilage in other five patients were positive but no FDG uptake. Biopsies of the tracheal/bronchial walls by bronchoscopy were all negative even though FDG uptakes increased in 17 patients. The intense uptake reduced or disappeared during steroid therapy for eight patients. In other two followed-up patients with symptomatic and inflammatory improvement, most FDG uptakes had diminished but two sides increased.