To the editor: The diagnosis of relapsing polychondritis may be difficult in the absence of typical auricular or nasal involvement. Airway involvement is a major cause of morbidity and mortality.
A 43-year-old man was admitted to our hospital because of a 2-month history of persistent fever and dry cough. He had a history of epilepsy at age 23 years, from which he recovered after treatment with sodium valproate. He also had a history of hearing loss for six months. During the 2 months before hospital admission, he had a fever of 38°C or higher nearly every day, and he was treated with antibiotics, but not effective. Physical examination revealed the patient with binaural hearing loss. The erythrocyte sedimentation rate (ESR) was 124 mm/h. The white cell count was 5.44 ×109/L, with 61.2% neutrophils. Pulmonary function showed obstructive ventilatory dysfunction. Hearing test showed the neural hearing loss. All culture, including blood, bone marrow and urine, was negative. The antinuclear antibodies level was normal. The chest and abdomen CT scan was normal. Therefore,18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) was performed to exclude malignancy and as a systemic search to explain fever of unknown origin. The imaging study revealed marked tracer uptake in all rib cartilages, as well as in the trachea, and major bronchi (Figure 1A). The maximum standard uptake value (SUVmax) of the respiratory tract was 3.68 (Figure 1B). Then we performed bronchoscopy, and found hypertrophy of the tracheal and bronchial mucosa (Figure 1C). Biopsy of tracheal rings by transbronchial needle aspiration (TBNA) showed an acute and chronic inflammatory process including infiltration of neutrophil cells, lymphocytes and plasma cells (Figure 1D), provided histological confirmation of the diagnosis. The patient's condition improved with the administration of corticosteroids. One week after daily intravenous infusion of 40 mg of methylprednisolone, the fever and dry cough disappeared and ESR returned to 32 mm/h.
In this case, 18F-FDG PET/CT clearly revealed the site of the inflammatory process, and then we got the pathological diagnosis by TBNA. Previously, only a few case reports have been published concerning the usefulness of FDG PET in the diagnosis of relapsing polychondritis.1–3 However, this is the first case reported using TBNA technique for obtaining the sample of tracheal cartilage. These findings suggest that 18F-FDG PET/CT is a useful radiological tool to assess the early respiratory involvement of relapsing polychondritis.
1. Nishiyama Y, Yamamoto Y, Dobashi H, Kameda T, Satoh K, Ohkawa M. [18F]Fluorodeoxyglucose positron emission tomography imaging in a case of relapsing polychondritis. J Comput Assist Tomogr 2007; 31: 381-383.
2. De Geeter F, Vandecasteele SJ. Fluorodeoxyglucose PET in relapsing polychondritis. N Engl J Med 2008; 358: 536-537.
3. Sato M, Hiyama T, Abe T, Ito Y, Yamaguchi S, Uchiumi K, et al. F-18 FDG PET/CT in relapsing polychondritis. Ann Nucl Med 2010; 24: 687-690.