Meningioma causing hyperostosis of the cranial convexity in a child.

We present an 8-year-old girl with meningioma-associated hyperostosis. The patient was referred to our clinic due to headache and a frontoparietal midline swelling that was more prominent on the right side of the cranium. A cranial MRI revealed a frontoparietal parasagittal meningioma, accompanied by a diffuse hyperostosis, that appeared to extend extracranially. She underwent a right frontoparietal craniotomy and the tumor, together with the affected bone, was successfully removed. The histological examination confirmed meningioma (World Health Organization 2007 Grade 1) in the intracranial and extracranial lesions. Meningioma causing hyperostosis in a child is rare. The precise mechanism of hyperostosis associated with meningioma remains unclear; however, the most widely accepted theory is that the tumor invades the bone.