Scientific Session 16 — Musculoskeletal ImagingWednesday, May 7, 2014
110. Imaging of Craniofacial Ossifying Fibroma With Pathologic Correlation
Foreman K1*, Murphey M1, Klassen M2 1. American Institute for Radiologic Pathology, Silver Spring, MD; 2. Joint Pathology Center, Silver Spring, MD
Address correspondence to K. Foreman (email@example.com)
Objective: The purpose of our study was to evaluate the imaging appearance of craniofacial ossifying fibroma and identify characteristic imaging features with pathologic correlation.
Materials and Methods: We retrospectively reviewed 15 patients with pathologically confirmed craniofacial ossifying fibromas. Radiologic studies were reviewed by two musculoskeletal radiologists with agreement by consensus and included radiography (n = 10), bone scintigraphy (n = 2), CT (n = 10) and MRI (n = 5). Evaluation included patient demographics, lesion location, size and morphology, and intrinsic features on CT and MRI. Imaging was correlated with available gross pathology (n = 10) and histology (n = 10).
Results: Patient age ranged from 1 to 52 years (average age, 20 years). There were eight male and seven female patients. Osseous location included mandible (47%), maxilla or maxillary sinus (33%), nasal bone (7%), skull (7%) and frontal sinus (7%). Lesions were round or oval lytic lesions with well-defined margins in all cases and showed variable degrees of expansile remodeling of bone. Lesion size ranged from 3 to 9 cm in maximal dimension (average, 5 cm). Multiple areas of matrix mineralization were present in all cases on CT and were commonly punctuate in character. The nonmineralized component showed similar attenuation to muscle. Fluid levels indicative of an aneurysmal bone cyst component were seen in 20% of lesions on CT or MRI. MRI characteristics included predominantly low or intermediate signal intensity on T1-weighting and heterogeneous intermediate or high signal intensity on T2-weighting. No soft tissue extension or significant surrounding marrow edema was present. There was diffuse heterogeneous moderate enhancement in all cases. The areas of punctuate mineralization corresponded to cementicles at pathologic evaluation in all cases.
Conclusion: The prospective diagnosis of craniofacial ossifying fibroma is often characteristic on imaging and can be differentiated from other diagnostic considerations such as fibrous dysplasia. These imaging features include a round or oval lytic craniofacial lesion with punctate areas of central mineralization but without soft tissue extension or surrounding edema. The areas of punctuate mineralization correspond to cementicles pathologically.