Frontal Sinus Osteoma Accompanied by Intracranial Mucocele and Local Hyperostosis Frontalis Interna.

Frontal sinus osteoma accompanied by intracranial mucocele and local hyperostosis frontalis interna has never been reported. A 47-year-old woman presented with a 3-month history of intermittent headache. Physical examination revealed no neurologic abnormality. Contrasted magnetic resonance imaging showed a frontal heterogeneously enhanced lesion with adjacent nonenhanced cyst. Computed tomography showed a bone density mass, which was accompanied by local hyperostosis frontalis interna, which filled the left frontal sinus and extended intracranially. The patient underwent a left frontobasal craniotomy. Both the osseous mass and cyst capsule were removed totally via a frontal craniotomy, followed by skull base reconstruction. The postoperative course was uneventful. The final pathologic diagnosis was osteoma and mucocele.