Osteofibrous dysplasia: clinicopathologic study of 80 cases.

A thorough review of the clinical, radiologic, and histologic features of 80 cases of long bone osteofibrous dysplasia is presented. Of the six cases of osteofibrous dysplasia immunostained with a cytokeratin antibody, two were cytokeratin positive; however, the five cases of fibrous dysplasia that were stained were all negative. Follow-up (mean, 5.4 years; range, 1 month to 31 years) data were available for 41 cases (51%). From the consultation series nine of the 18 patients studied had recurrences, regardless of the different treatment regimens. The average recurrence interval in these patients was 2.7 years. Two patients had incomplete excision and six had biopsy only. All eight of these patients had residual tumors. Among the 16 Mayo Clinic patients, one had recurrence 5 years after the initial treatment. In two cases, 7-year-old and 6-year-old boys, histologic maturation to fibrous dysplasia was observed 4 and 10 years later, respectively. Adamantinoma has not developed in any of the 41 cases of osteofibrous dysplasia for which we have follow-up information. It seems clear that osteofibrous dysplasia does not progress to adamantinoma. Our study suggests that osteofibrous dysplasia is probably a variant of fibrous dysplasia, as demonstrated by the maturation of two lesions of osteofibrous dysplasia to fibrous dysplasia. Surgical treatment may be appropriate in cases with an extensive lesion, pseudoarthrosis, and accentuated tibial bowing. The overall prognosis is good, even with recurrence.