A case of relapsing polychondritis associated with auricular cartilage infiltration of immunoglobulin G4-positive plasma cells and lung cancer.

A 79-year-old man was diagnosed with relapsing polychondritis, from symptoms of bilateral auricular deformity and pigmentation, polyarthralgia, and audiovestibular damage, and from histological examination of the left auricular cartilage. The left auricular cartilage biopsy specimen revealed cartilage destruction with infiltration of plasmacytes expressing IgG4. This case suggests that IgG4 may be involved in the pathogenesis and etiology of relapsing polychondritis.