FDG-PET/CT and Auricular Cartilage Biopsy Are Useful for Diagnosing with Relapsing Polychondritis in Patients without Auricular Symptoms.

Saki Okuda,Koji Kinoshita,Itaru Matsumura,Masanori Funauchi,Masafumi Sugiyama,Tetsu Itami,Yuji Nozaki,Yasuaki Hirooka

doi:10.3390/life11090956

Abstract

Relapsing polychondritis (RP) is a rare autoimmune inflammatory disease characterized by recurrent inflammation and destruction of cartilage. Although auricular chondritis is a characteristic finding in RP, it can be difficult to diagnose in the absence of auricular symptoms. A 64-year-old Japanese male was referred to our hospital with fever and respiratory distress. Contrast-enhanced computed tomography (CT) revealed bronchial wall thickening and we suspected RP; however, he had no auricular symptoms and did not meet the diagnostic McAdam criteria for RP, so we used 18F-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) to search for other cartilage lesions. This analysis revealed FDG accumulation not only in the bronchial walls, but also in the left auricle. Instead of a bronchial biopsy using a bronchoscope, we performed a biopsy of the left auricular cartilage, which is considered a relatively less invasive site. Even though the auricle was asymptomatic, the pathology results revealed chondritis. He was diagnosed with RP, and his symptoms rapidly improved with corticosteroid therapy. A biopsy of asymptomatic auricular cartilage may be useful in the diagnosis of RP. FDG-PET/CT is a powerful tool for the early diagnosis of RP, identifying inflammatory areas even in the absence of symptoms, and guiding the selection of appropriate biopsy sites.

Highlights

Relapsing polychondritis (RP) is a rare autoimmune inflammatory disease characterized by recurrent inflammation and destruction of the cartilage in various sites of the body, including the auricle, nose, throat, trachea, and bronchi [1]
We report the case of a patient with asymptomatic FDG accumulation in the auricle on FDG-PET/computed tomography (CT), and we describe the auricular cartilage biopsy that allowed a definitive diagnosis of RP
Laryngotracheobronchial involvement is seen in 30–50% of patients with RP, and RP patients with significant laryngotracheobronchial involvement have a poor prognosis [5]

Summary

Introduction

Relapsing polychondritis (RP) is a rare autoimmune inflammatory disease characterized by recurrent inflammation and destruction of the cartilage in various sites of the body, including the auricle, nose, throat, trachea, and bronchi [1]. (d–i) FDG-PET/CT findings of the left auricle, costal cartilage, larynx, and tracheal and bronchial walls before the start of treatment. To further investigate the lesions in RP, we performed FDG- PET/CT, which revealed FDG accumulation in the tracheal and bronchial walls, and in the left auricle, larynx, and costal cartilage (Figure 1d–g). The auricle was asymptomatic, but the pathological results showed cartilaginous infiltration of inflammatory cells and calcification in line with the presence of osteochondritis (Figure 2) Based on these results, we made the diagnosis of RP. A blood test on day 15 showed that the patient’s CRP level had decreased to the reference level, and a contrast-enhanced CT scan on day 36 demonstrated that the wall thickening of the trachea and bronchi had improved (Figure 1c).

Discussion

Findings

Conclusions