Giant skull base atypical meningioma presenting with rapidly progressive impaired consciousness caused by severe venous congestion: case report.

A 43-year-old female presented with a giant skull base atypical meningioma manifesting as rapid progression of impaired consciousness. The meningioma was located in the ethmoid sinus, sphenoid sinus, nasal cavity, and left middle temporal fossa, and the intracranial portion of the tumor involved the left temporal region with massive surrounding brain edema in the left temporal lobe and basal ganglia. She underwent emergent fronto-temporo-parietal decompressive craniectomy, and the intracranial portion of the tumor was resected to control intracranial pressure. She recovered consciousness and neurological function dramatically, and subsequently underwent radical tumor resection via combined extended transbasal and left lateral transzygomatic infratemporal fossa approaches one month after the initial surgery. The extensive brain edema completely disappeared after tumor resection, and the patient fully recovered without neurological deficits except anosmia and small visual field defect. Rapid neurological deterioration and disturbance of consciousness caused by extensive peritumoral brain swelling are unusual in meningioma. In this case, the extemporaneous decompressive craniectomy was highly useful in the management of increased intracranial pressure.