meningioma
Pronunciation: meh-nin-jee-OH-mah
Benign tumor arising from meningothelial cells of the arachnoid mater, representing the most common primary intracranial tumor in adults.
Full Definition
Meningioma is a typically benign neoplasm originating from the meningothelial cells of the arachnoid membrane surrounding the brain and spinal cord. These tumors account for approximately 30% of all primary intracranial tumors and show a strong female predominance. Histologically, meningiomas display various architectural patterns including meningothelial, fibrous, transitional, and psammomatous subtypes. While most are WHO Grade I (benign), atypical (Grade II) and anaplastic (Grade III) variants exist with increased mitotic activity and aggressive behavior.
Usage
Usage note: Always specify WHO grade when diagnosed; avoid confusing with other dural-based tumors.
In Context
- "The pathologist identified whorled patterns and psammoma bodies characteristic of a Grade I meningioma." — Histopathology report
- "Atypical meningioma was diagnosed based on increased mitotic figures and brain invasion." — Surgical pathology consultation