meningioma
Pronunciation: meh-nin-jee-OH-mah
A tumor arising from the meningeal coverings of the brain and spinal cord, typically benign but occasionally malignant.
Full Definition
Meningioma is the most common primary brain tumor in adults, originating from the arachnoid cap cells of the meninges. These tumors are classified as WHO grades I, II, or III, with grade I representing benign lesions comprising 80% of cases. Meningiomas typically present as well-circumscribed, dura-based masses that compress rather than invade brain tissue. They frequently calcify and enhance uniformly with contrast on imaging. Treatment involves surgical resection when symptomatic, with the Simpson grading system used to assess completeness of removal and predict recurrence risk.
Usage
Usage note: Always specify location and WHO grade when clinically relevant.
In Context
- "The parasagittal meningioma was approached via an interhemispheric corridor." — surgical technique description
- "Simpson grade I resection of the sphenoid wing meningioma was achieved." — operative note