Unusual manifestation of an osteoid osteoma of the capitate

A case of osteoid osteoma of the capitate in a 29-year-old male is reported . The patient suffered from unspecific clinical findings and a 3-year histo ry of uncharacteristic wrist pain. Conventional radiographs of the wrist re vealed a circumscribed sclerosis in the proximal part of the capitate bone beside a diffuse demineralisation of the carpal bones. Magnetic resonance i maging demonstrated a circumscribed, tumorous lesion with marked enhancemen t after IV administration of contrast agent and a highly calcified nidus, w hich was sharply demarcated by a small rim of granulation tissue from the s urrounding spongious bone. Based on MRI findings, the diagnosis of an osteo id osteoma was established and confirmed after operation and histologic ana lysis.