Monostotic Fibrous Dysplasia of the Clivus: Image-Guided Endoscopic Endonasal Transsphenoidal Surgery

Introduction: Fibrous dysplasia is a non-heritable, congenital disease involving the bones. Its diagnosis relies on image examination and pathology. Treatment is usually conservative, but in cases of cranial nerve impingement or extension to the condyles, surgery should be considered. In this paper, we describe a singular case of monostotic fibrous dysplasia of the clivus in a child. Case Report: A 14-year-old boy presented with chronic headache and diplopia. A neurological examination revealed palsy of the right VIth cranial nerve. The radiological findings were consistent with fibrous dysplasia, with a hypointense and isointense clival lesion on T-1-and T-2-weighted images, respectively. Surgical treatment was indicated by cranial nerve impairment. An endoscopic endonasal approach with an image-guided system was used. The patient was discharged four days after surgery and his diplopia improved postoperatively. Discussion: A variety of surgical approaches have been used in the treatment of midline extra-axial cranial base tumors. Fibrous dysplasia of the clivus without expansion to the condylus can be removed with a transsphenoidal endonasal endoscopic approach. Preoperative imaging reveals the individual patient's anatomy and improves the intraoperative orientation. Conclusion: Image-guided transsphenoidal endoscopic surgery is recommended for its safety and minimal invasiveness.