Osteoid osteoma: clinical and investigative features.

From 1979 to 1988, 15 cases of osteoid osteoma were diagnosed and treated at our hospital. There were 10 males and 5 females, the average age at the time of diagnosis was 17.2 years (from 5 to 54 years). The clinical features were night pain and localized pain in most cases. There was distinct pain relief by salicylate in 58% of the patients with a therapeutic trial. The duration of symptoms before diagnosis averaged 17.9 months (from 1 month to 10 years). Most of the lesions were located in the lower extremities, predominantly in the femur. The hip was a commonly affected site in children and young adults. The X-ray findings in the affected area were classical of the lesion in only 47% of the cases, therefore, preoperative localization of the nidus was aided by either tomography or CT scan. Intraoperative localization by use of an image intensifier and by taking X-rays of the excised specimen has proven to be reliable. All cases underwent en bloc resection of the lesion, and all of the patients were symptom free immediately after the operation, except for one recurrence. A second operation was performed in this case 2 years later and was successful, with pathological confirmation. Fourteen tumors were confirmed by histopathological study, one case could not be confirmed by pathological examination, however the patient obtained complete relief of symptoms postoperatively.