[Variants in the growth of meningiomas of the base of the skull spreading into the orbit and paranasal sinuses].

Meningiomas of the skull base involving the orbit and paranasal sinuses were diagnosed in 254 patients. The patients were operated on in 1982-1991. All craniocephalic meningiomas involve the anterior skull base bones. The involvement presents either as destruction (nodular tumor) or as hyperostosis (infiltrative growth of the tumor). All patients were divided into 8 groups with different location of skull bones involvement. A classification of meningiomas of skull base disseminating into the orbit and paranasal sinuses is proposed, proceeding from the anatomical principle. This classification helps plan a surgical access, scope of intervention, probable size of skull defect and method of its closure, possible postoperative functional and cosmetic defects.