Relapsing polychondritis (RP) is an uncommon autoimmune disease that causes inflammation of the cartilage and proteoglycan-rich structures, including the ear, nose, and airway. Paraneoplastic RP is a subset of RP that occurs in some individuals following the detection and treatment of certain types of cancers. FDG PET/CT helps with early diagnosis of RP, identifying inflammatory areas even in the absence of symptoms, and guiding the selection of appropriate biopsy sites. Here, we present a case of adenocarcinoma of the lung presenting with paraneoplastic symptoms of RP as initial presentation, and symptoms were resolved after 3 cycles of chemotherapy.