Osteoid osteoma is a small, benign, and painful tumor most commonly af
fecting the extraarticular portions of the long bones, especially the
femur or tibia. Osteoid osteoma of the elbow is uncommon. In this arti
cle a 19-year-old man with an osteoid osteoma of the distal humerus is
presented to illustrate the diagnostic problems and unusual radiograp
hic features of an intraarticular osteoid osteoma.