Introduction: Ossifying fibroma is a rare benign fibro-osseous lesion that usually affects mandible and maxillary bone. Their localisation to paranasal sinus and skull base is uncommon.
Material and method: We report a huge recurrence of ossifying fibroma of the ethmoid paranasal sinus involving the skull base.
Case report: Ten years after the removal of ossifying of the ethmoid 34 year old man presented headache with diplopia. Computed tomography (CT) and magnetic resonance imagery (MRI) showed a recurrent tumour witch extended to the nasal cavity, the sphenoid and the posterior ethmoid sinuses, and the skull base. The tumour was totally removed using an anterior subcranial approach with removal of the orbital rim. Histopathology confirmed an ossifying fibroma. Two years later a subdural empyema with frontal suppuration necessited to remove the frontal bone flap, which was re-constructed 12 months later using a synthetic material.
Conclusion: Ossifying fibroma is a rare, benign tumour witch may recur if incomplete resection is performed. A long follow up with CT scan and MRI is required.