Tentorial meningiomas.

Tentorial meningiomas are encountered relatively infrequently, but it is nonetheless important to be aware of their variable clinical presentations and the need for individualized preoperative assessment and surgical management. The challenges presented by these lesions are due in large part to the complexity and variety of neurovascular structures associated with the tentorium. As is true for all meningiomas, the goal of operation is complete resection with limited morbidity and mortality. Preoperative assessment with CT or MR imaging or both and angiography with embolization, when possible, is advocated for all patients. The choice of surgical approach is dictated by the location of the lesion, dural origin, and involvement of major neurovascular structures. With extended surgical approaches, combining infratentorial and supratentorial exposure, one can attempt complete tumor resection even in patients with extensive skull base involvement. However, if complete resection presents an unacceptable risk of neurologic morbidity, one must consider adjuvant therapy. Radiotherapy (conventional external beam or stereotactic) has been shown to be of some benefit in stabilizing residual disease or delaying recurrence; adjuvant chemotherapy with antiprogesterone agents is still undergoing clinical evaluation.