Osteoid osteoma and benign osteoblastoma in childhood

SUMMARY Three cases of osteoid osteoma and one ofbenign osteoblastoma in children are described. The main complaint was severe pain which was worse at night; it was relieved by aspirin or other analgesics. The diagnosis was made on clinical and radiological grounds and was confirmed on histological examination of the central nidus removed at operation. The pain was relieved in the patients with osteoid osteoma, and it was very much less after operative removal of the benign osteoblastoma. Both conditions are probably variations of the same disease process, depending on the anatomical site and the type of bone affected. Osteoid osteoma was described as a clinical entity in 1935 by Jaffe, and then more fully by Jaffe and Lichtenstein (1940). In 1932 Jaffe and Mayer reported a patient in whom the disease differed somewhat from osteoid osteoma, and Dahlin and Johnson (1954) further described such cases and used the term 'giant osteoid osteoma'. The term benign osteoblastoma was introduced by Jaffe (1956) and Lichtenstein (1956) independently to differen-tiate this condition from osteoid osteoma. Since then numerous reports on both conditions have appeared, mainly in orthopaedic and radiology journals. In our experience children with these conditions are referred about equally to general paediatric and orthopaedic clinics. Nevertheless the clinical picture, which is similar in both osteoid osteoma and benign osteoblastoma, appears to be unfamiliar to many paediatricians. It was for this reason, and also because of the inherent difficulty in making the diagnosis, that we describe our experience with three patients with osteoid osteoma and one with benign osteoblastoma seen in Sheffield during the last 12 years. Case reports Case 1. Osteoid osteoma, left femur. This boy was born on 2 October 1958 and was first seen at the orthopaedic clinic at age 7i years with a history of pain in the left thigh and a limp for a year. The pain was not constant and was relieved by aspirin. A