Fibrous Dysplasia and Ossifying Fibroma - an advent in their diagnosis

Objectives: Fibro-osseous lesions of the craniofacial complex comprise of a diverse, interesting and challenging group of conditions that pose difficulties in classification and treatment. The two most confused benign fibro-osseous lesions are fibrous dysplasia and ossifying fibroma. Sometimes, the classic clinical, radiologic or pathologic features of fibrous dysplasia or ossifying fibroma may not be evident, but overlapping features of both may be seen. The dilemma in diagnosis of these lesions rests in the bony trabeculae as well as in the fibrous stroma. Cases of fibrous dysplasia showing lamellated bony trabeculae and osteoblastic rimming have been reported which may confound diagnosis because of resemblance with ossifying fibroma. In the present study, an attempt has been made to demonstrate the fibrous element of these two lesions using histochemical stains. Study design: The sections of fibrous dysplasia & ossifying fibroma were stained with Haematoxylin and Eosin, Trichrome stain and Peracetic acid-aldehyde fuschin-modified Halmi stain. Result: The study revealed that the oxytalan fibers were more numerous in ossifying fibroma (seen with both Trichrome and modified Halmi stains). Conclusion: Although the ultimate diagnosis of fibrous dysplasia and ossifying fibroma is arrived at by correlating clinical, radiographic and routine histopathologic examination, the differences in the configuration of the stroma using histochemical stains may help in the diagnosis of these two lesions.