Relapsing polychondritis with isolated tracheal involvement: Imaging findings on CT, MRI, and PET-CT: A case report and literature review.

Relapsing polychondritis (RP) is a rare autoimmune disorder characterized by recurrent inflammation and progressive destruction of cartilage-rich tissues. While auricular and nasal cartilage are commonly affected, isolated involvement of the trachea and main bronchi is exceedingly rare. We present the case of a 53-year-old female with low-grade fever, sore throat, and nonproductive cough. Laboratory results showed elevated inflammatory markers, including C-reactive protein (CRP), rheumatoid factor, and interleukin-6 (IL-6). Imaging studies CT, MRI, and PET-CT revealed irregular thickening and stenosis of the tracheal and bronchial cartilage rings. The patient responded favorably to glucocorticoids and immunosuppressive therapy, with significant improvement noted on follow-up imaging. This case emphasizes the importance of a thorough diagnostic approach in recognizing RP with atypical respiratory involvement.