Abstract
Osteoid osteomas are benign, solitary bone-forming tumors associated with progressively worsening pain. The exact etiology remains unclear, although it is speculated to result from neoplasia, direct trauma, or an inflammatory process. We present a rare case of a 53-year-old male who presented to the ED with a one-year history of worsening right ear pain and no significant medical or surgical history. On physical examination, the right mastoid area was tense and swollen, without signs of inflammation. Following an enhanced and non-enhanced CT, a diagnosis of an osteoid osteoma was established. This case report contributes imaging data regarding this unusual location for an osteoid osteoma.