Low-Grade Astrocytoma Causing Dural and Calvarial Destruction.

Most of the literature on intra-axial lesions causing calvarial and dural destruction comes from case reports for glioblastoma, lymphoma, metastasis, and aggressive meningioma. Destruction of dura and calvaria by low-grade gliomas is extremely uncommon; cases reported so far have been mostly oligodendrogliomas. This article describes the unusual case of a 23-year-old male patient with a left-sided intra and extracranial tumor involving the frontal lobe, destroying the overlying dura and calvaria, who underwent maximal safe resection. Histopathology showed the tumor to be a low-grade astrocytoma. The calvarial thinning or remodeling caused by low-grade gliomas is thought to result from their chronic mass effect, by displacing the overlying layer of cerebrospinal fluid and transmitting brain pulsations directly to the inner table of the skull. Pressure thinning of the inner table of the skull may be caused by Pacchionian granulations close to the midline. Although this is extremely uncommon, magnetic resonance imaging may include low-grade astrocytoma in the differential diagnosis in such cases.