Relapsing Polychondritis With Increased Bone Marrow Signal on Magnetic Resonance Imaging in a 13-Year-Old Girl.

Relapsing polychondritis (RPC) is an inflammatory disorder predominantly affecting cartilaginous structures including ears, nose, joints, and respiratory tracts. Although RPC is rare in children, previous reports indicated childhood RPC is atypical or severe. A 13-year-old girl presented with redness and swelling of the bilateral auricles and subsequently developed arthralgia of multiple joints. Histopathologic findings of the auricular cartilages were compatible with RPC. Magnetic resonance imaging (MRI) for the evaluation of arthralgia unexpectedly demonstrated increased bone marrow signal of metacarpals and the distal epiphysis of radii and ulnae. Although arthritis in RPC has not been well evaluated with magnetic resonance imaging, increased bone marrow signal has been reported in a child with RPC without an underlying disease. Thus, this could be another finding of RPC itself. Evaluation of more patients with magnetic resonance imaging would elucidate if this is an additional atypical finding of childhood RPC.