Osteofibrous Dysplasia Differential Diagnoses

Updated: Aug 17, 2021
  • Author: Darin Davidson, MD; Chief Editor: Omohodion (Odion) Binitie, MD  more...
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Diagnostic Considerations

The differential diagnosis of osteofibrous dysplasia includes the following conditions:

  • Monostotic fibrous dysplasia
  • Nonossifying fibroma
  • Adamantinoma

Fibrous dysplasia can be differentiated on the basis of several characteristics. Generally, it occurs in patients older than 10 years, more commonly affects the femur and ribs, and does not resolve spontaneously. [41]  Radiographically, it appears as an intramedullary lesion with a ground-glass appearance. [42] On histologic examination, fibrous dysplasia is not bordered by active osteoblasts and is cytokeratin-negative. [43] Cytogenetically, it is related to anomalies affecting chromosomes 3 and 5. Sakamoto et al found that immunoreactivity for osteonectin in bone matrix is seen more commonly in osteofibrous dysplasia. [44]

Nonossifying fibroma can be distinguished from osteofibrous dysplasia by several typical features. Nonossifying fibroma is predominantly a metaphyseal lesion. Histologically, it is characterized by a storiform pattern of spindle cells with scattered multinucleated giant cells, is not bordered by active osteoblasts, and is cytokeratin-negative.

More challenging is the distinction between osteofibrous dysplasia and adamantinoma [45] ; these two conditions can appear very similar both clinically and pathologically and are sometimes confused with each other. The distinction between them is important because adamantinoma is a low-grade malignancy that must be managed more aggressively.

Adamantinoma has a similar predilection for the cortex of long bones, particularly the tibia, and may have radiologic and histologic findings similar to those of osteofibrous dysplasia. [46, 47, 48] However, adamantinoma can be distinguished from osteofibrous dysplasia by the presence of soft-tissue extension, intramedullary involvement, periosteal reaction in the absence of pathologic fracture, and the histologic finding of hyperchromatic epithelial islands. Adamantinoma typically manifests with a larger, more painful lesion and is usually found in patients older than 10 years.

As suggested by Kuruvilla and Steiner, however, it is likely that osteofibrous dysplasia is part of the morphologic spectrum of adamantinoma. [49] Kanamori et al found that extra copies of chromosomes 7, 8, 12, 19, and 21 recur in adamantinoma. [50] These aneuploidies may be useful in differentiating adamantinoma from osteofibrous dysplasia.

A review article by Most et al [51] on the similarities and differences between the two entities described immunohistochemical and ultrastructural evidence demonstrating that the neoplastic cell in adamantinoma derives from an epithelial lineage. Subsequently, published reports [49, 52, 53] described another clinical entity—differentiated or osteofibrous dysplasia–like adamantinoma—that appears to lie between osteofibrous dysplasia and adamantinoma along a spectrum of disease.