Fibrous Dysplasia of the Clivus: Case Report and Literature Review.

Fibrous dysplasia is a benign, developmental bone disorder that causes fibrous replacement of normal skeletal tissue. This may lead to weakness, distortion, and tissue expansion. Fibrous dysplasia can occur anywhere in the body, including the craniofacial area. The clivus is a central skull bone formed by the bases of the sphenoid and occiput, respectively. The clivus is a rare, usually unrecognized, and seldom reported location for the development of fibrous dysplasia. Although fibrous dysplasia of the clivus (FDC) is usually discovered by incidental findings, it can sometimes present with clinical symptoms. In this case, we discuss a 30-year-old male who presents to the emergency room with headaches, altered mental status, and a prior presentation of location-related symptomatic epilepsy. Magnetic resonance imaging depicted a mass in the clivus, low in signal on T1 and mildly hypointense on T2 imaging. Follow-up computed tomography (CT) imaging, as recommended, revealed the classic presentation of FDC. In this paper, we discuss the significance of this condition and the importance of thorough investigation to rule out differential diagnoses that may present with similar acute symptoms as this patient.