Select the Simpson grade based on intraoperative findings to predict the long-term recurrence profile.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Standardized operative note documentation immediately following meningioma resection.
Determining the need for post-operative adjuvant surveillance vs stereotactic radiosurgery (SRS).
Section 2
Literature
Development
Published by Donald Simpson in 1957. Meningiomas were largely thought of as "benign" tumors that were easy to cure. Simpson observed that surgeons who merely plucked the tumor out of the skull (Grade 3) had extraordinarily high recurrence rates because microscopic tumor cells deeply invade the origin dura. He proved that to achieve true oncological cure (Grade 1), the brain envelopes themselves (dura/bone) must be aggressively excised.
Section 3
Pearls/Pitfalls
Modern Controversy (Simpson vs SRS)
In 1957, Grade 1 (excising the sagittal sinus or drilling out the skull base) was justifiable because there were no alternatives. Today, achieving a Grade 4 (subtotal resection) safely to protect a cranial nerve and then blasting the remnant with Gamma Knife (SRS) yields tumor control rates nearly identical to a Grade 1 resection, without the devastating skull-base surgical morbidity.
Section 4
Evidence Appraisal
Primary Reference
The recurrence of intracranial meningiomas after surgical treatment
Simpson D • J Neurol Neurosurg Psychiatry. 1957;20(1):22-39
