Purpose: The authors sought to identify radiological criteria assisting in the diagnosis of craniofacial fibrous dysplasia and differential diagnosis of fibro-osseous lesions by comparing computed tomography (CT) and magnetic resonance imaging (MRI) findings and histological results in 23 patients with presumed fibrous dysplasia.
Materials and methods: From February 2000 to March 2005, 23 patients (17 women and six men, aged 9-66 years) with facial bone disease underwent CT and MRI studies. Imaging findings were compared with the results of histological examination performed within 1 month of the radiological diagnosis.
Results: The combination of CT and MRI led to a presumptive diagnosis of fibrous dysplasia in all cases, but histology confirmed the diagnosis in 18 cases only. In two cases that had initially been considered cyst-like variants of fibrous dysplasia and were associated with irregular enhancement at MRI, histology characterised the lesions as single locations of multiple myeloma. In one case, targeted biopsy of areas showing intense enhancement led to a diagnosis of low-grade fibrosarcoma; in the remaining two cases, the definitive diagnoses were ossifying fibroma and myeloproliferative disease.
Conclusions: MRI proved useful in differentiating fibrous dysplasia from other bone diseases, defining clinical behaviour, identifying neoplastic foci within dysplastic tissue and distinguishing benign from malignant bone lesions. The authors suggest a broader use of contrast-enhanced MRI for the diagnosis and follow-up of dysplastic lesions of the facial bones and for planning appropriate surgical treatment.