The roentgen appearance of benign osteoblastoma.

Abstract

This paper records an attempt to determine the roentgenologic features of benign osteoblastoma through a review of the literature and personal experience with 4 new cases of this uncommon and interesting bone tumor. Two writers (1, 3) state that this neoplasm has no characteristic roentgen appearance, while another (6) holds an opposite opinion. There has been no review of a representative volume of cases in an attempt to resolve these differences. Histologically, benign osteoblastoma is characterized by the presence of well vascularized osteoid and bone-forming tissue which bears a certain similarity to osteoid osteoma (3). However, benign osteoblastoma differs significantly both clinically and roentgenographically from the classical osteoid osteoma (3, 6). To date there have appeared in theliterature about 30 cases of benign osteoblastoma (1–6). Lichtenstein (6) carefully analyzed the material reported by Dahlin and Johnson (1) under their designation “giant osteoid osteoma.” It was his opinion that most of their cases were without doubt benign osteoblastomas and that only a few could be interpreted as genuine osteoid osteomas. A study of the roentgenographic reproductions in Dahlin's cases, in our opinion, lends support to Lichtenstein's view. It appears that at least 7 are acceptable examples of benign osteoblastoma according to the criteria outlined by Jaffe (3). Golding and Sissons (2) reported 2 cases, and Kirkpatrick and Murray (5) reported another, under the heading “osteogenic fibroma.” Jaffe published 10 cases and Lichtenstein an equal number. As pointed out by Jaffe and Lichtenstein, the name benign osteoblastoma is a suitable designation for this uncommon neoplasm of bone. It should not be confused with the so-called “ossifying fibroma” which is apparently closely related to fibrous dysplasia and usually localized in the maxilla or the mandible (3). Benign osteoblastoma is a neoplasm which is usually adequately treated either by conservative surgery, e.g., curettage or radiation therapy. Of the 30 cases reported many have been followed for relatively long periods of time—six years (2), ten years (3), and fourteen years (1), all without recurrence. In only 1 case, which was described by Lichtenstein, was recurrence observed. This took place after an interval of nine years. Despite its benign nature, the tumor is an actively growing neoplasm which can give rise to serious consequences. For example, local compression of neighboring structures, when the location is in the spine, can produce neurologic syndromes due to pressure on the cord (1–6). The most common clinical complaints are dull, insidious pain and local tenderness, accompanied by a soft-tissue swelling. Associated swelling of adjacent joints was reported in 2 cases (1). The duration of symptoms is usually only a few months (3).