CT and MR imaging of giant cell granuloma of the craniofacial bones.

Background and Purpose: Giant cell granuloma (GCG) is a rare lesion. The purpose of this study was to determine the CT characteristics and describe possible MR imaging features of GCG of the craniofacial bones.
Methods: We retrospectively reviewed 7 CT studies and 1 MR imaging study of 7 histologically proved cases of GCG in 2 men, 3 women, and 2 patients of unknown gender, aged 12-51 years, during a period of 10 years, from 1995 to 2005.
Results: The granulomas predominantly involved the maxilla in 3 patients, the mandible in 2 patients, the temporal bone in 1 patient, and the nasal cavity in 1 patient. These lesions on imaging were expansile masses that demonstrated adjacent bone wall thinning, and most were associated with lytic bone destruction. They were predominantly masses with soft-tissue attenuation on CT scans and may have infiltrated the surrounding soft-tissue structures. The patient with an MR imaging had a lesion that was hypointense on both T1- and T2-weighted MR images. The lesions revealed avid homogeneous contrast enhancement.
Conclusion: The imaging features of GCG are nonspecific. However, this entity should be included in the differential diagnosis of expansile lesions in the craniofacial bones.