Frontoethmoidal Osteoma with Secondary Intradural Mucocele Extension Causing Frontal Lobe Syndrome and Pneumocephalus: Case Report and Review of Literature

Background Paranasal sinus osteoma is a common, asymptomatic, histologically benign, slow-growing tumor. However, it can give rise to secondary pathologies such as a mucocele in about 50% of the cases. Rarely, intracranial and orbital extension is present, leading to rhinoliquorrhea, pneumocephalus, or neurologic and visual impairment, which might be potentially life-threatening. Case Description A 49-year-old man presented with an acute frontal lobe syndrome and rhinoliquorrhea. Cranial magnetic resonance tomography showed a suspected frontoethmoidal osteoma with a mucocele expanding intradurally into the left frontal lobe. It was accompanied by pneumocephalus and showed communication with the left lateral ventricle. Through a bifrontal craniotomy, in toto resection of the frontoethmoidal bony tumor and the intradural mucocele was performed, while thereafter the frontal sinus was cranialized using a pedunculated periosteal flap. Postoperative recovery was uneventful with complete resolution of the tension pneumocephalus and rhinoliquorrhea and led to an improvement of the frontal lobe syndrome. Conclusions We present a rare case of pneumocephalus caused by a frontoethmoidal osteoma associated with an intradural mucocele. A review of the literature, focusing on the surgical strategies in such cases, is provided.