A Case of Fibrous Dysplasia Simultaneously Involving the Sphenoid Sinus and the Clivus

Fibrous dysplasia is an uncommon benign bone disorder in which normal medullary bone is replaced by fibrotic and osseous tissue. Limited involvement of the sphenoid sinus or the clivus is extremely unusual. Here, we present a case of fibrous dysplasia in a 46-year-old female that involved the sphenoid sinus and the clivus simultaneously. Imaging modalities demonstrated an expansile lesion filling the entire left sphenoid sinus, extending to the clivus. Biopsy specimen was obtained by endoscopic sphenoid sinusotomy, and it showed extensive spindle-shaped fibroblastic cells with irregularly shaped trabeculae of woven bone which was compatible with fibrous dysplasia. After 6-month follow-up, the patient displayed no evidence of recurrenceope