Microsurgical Resection of a Primary Intraosseous Meningioma Encasing the Superior Sagittal Sinus.

Primary intraosseous meningiomas (PIMs) are an infrequent variant of meningiomas characterized by hyperostosis and brain compression. En bloc surgical resection of giant PIMs involving critical structures such as venous sinuses or cranial nerves could be associated with significant morbidity. The objective of this report is to demonstrate the safety and feasibility of piecemeal resection of PIMs involving the superior sagittal sinus and frontal sinus. A 54-year-old female with a large 5 cm thick bifrontal primary intra-osseous meningioma encasing the anterior segment of the superior sagittal sinus and frontal sinus underwent a bifrontal craniotomy with piecemeal microsurgical resection of the lesion, complete frontal sinus exoneration, and a synthetic cranioplasty. Clinical outcome was measured by extent of resection, preservation of cortical draining veins and postoperative course. A Simpson grade I resection of the lesion was achieved following piecemeal resection of the giant PIM without clinical or radiographic evidence of venous infarct or injury. The postoperative course was uncomplicated, and the patient was discharged home 3 days after cranioplasty. A complete resection of a giant bifrontal PIM with superior sagittal sinus encasement and frontal sinus involvement can be achieved safely via a piecemeal approach without significant intra-operative morbidity.