Osteoplastic Flap without Obliteration for Massive Fronto-orbital Fibrous Dysplasia: A Novel Surgical Approach, Case Report, and Literature Review

Fronto-orbital fibrous dysplasia is a rare condition with complex management. We report a case of massive frontal sinus fibrous dysplasia with extensive orbital involvement treated with osteoplastic flap without frontal sinus obliteration. We also review and discuss the literature regarding the management of these lesions with attention to malignant conversion.

A 20-year-old male initially presented with acute right orbital ptosis, diplopia, swelling, edema, and erythema. Emergent imaging demonstrated a right superior orbital mucopyocele in the setting of a massive fibro-osseous lesion involving the entire frontal bone and both orbits, concerning for fibrous dysplasia. He underwent a right anterior orbitotomy with removal of the mucocele to decompress the orbit. The patient elected conservative observation and serial evaluation of the primary fibro-osseous lesion.

Over the subsequent two years, his right ptosis progressed and frontal bossing developed. At age 22 he reported progressive worsening of symptoms including orbital asymmetry and periorbital swelling. He remained neurologically intact with no visual deficits. Surveillance CT imaging demonstrated interval growth of the fibro-osseous lesion. He elected surgical management.

The patient underwent a bicoronal osteoplastic flap without frontal sinus obliteration, including resection of the frontal lesion, bilateral orbital roof decompression, and a concurrent endoscopic Draf 3 frontal sinusotomy with mucosal grafting of the frontal sinus posterior table. He tolerated the procedure well and was discharged home on the first postoperative day. Pathology revealed benign fibrous dysplasia. Postoperative imaging revealed bilateral orbital decompression and wide lesion resection with residual disease in the most lateral portions of the frontal sinuses.

This lesion the final pathology did not indicate malignant conversion. Malignant change in fibrous dysplasia is very rare, and its frequency was estimated to be just 0.5% for monostotic fibrous dysplasia and 4% for McCune–Albright syndrome (Hoshi 2006). This case highlights the importance of close follow-up and surveillance imaging in FD malignant.