Instrcapsular epiphyseal osteoid osteoma of ankle joint. A case report.

A 12-year-old boy with ankle pain following minor trauma was found after a month of conservative treatment to have a small sclerotic lesion in the anterolateral distal tibial epiphysis. At operation, a vascular, raised, intracapsular epiphyseal lesion was removed. Microscopic examination revealed an osteoid osteoma. To the authors' knowledge no previous example of intracapsular epiphyseal osteoid-osteoma has been reported.