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

• Main Authors: Saki Okuda, Yasuaki Hirooka, Tetsu Itami, Yuji Nozaki, Masafumi Sugiyama, Koji Kinoshita, Masanori Funauchi, Itaru Matsumura
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Life
• Subjects: relapsing polychondritis; diagnosis; auricular cartilage; biopsy; FDG-PET/CT
• Online Access: https://www.mdpi.com/2075-1729/11/9/956

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.