Overview
This lecture covers the Simpson grading scale, a classification system used by neurosurgeons to describe the extent of meningioma tumor resection and its impact on recurrence rates.
Simpson Grading Scale Overview
- The Simpson grading scale is used to classify the extent of surgical resection of meningiomas.
- The scale ranges from grade 1 to grade 5, with grade 1 being the most complete resection.
Simpson Grades Explained
- Grade 1: Complete removal of the tumor and its dural attachment (the tumor's origin).
- Grade 2: Complete tumor removal with coagulation (burning) of the dural attachment, but not removing it.
- Grade 3: Complete tumor removal but leaving the dural attachment untreated.
- Grade 4: Subtotal resection; only part of the tumor is removed.
- Grade 5: Only a biopsy is performed; tumor is not resected.
Clinical Relevance
- Simpson grade correlates with meningioma recurrence rates—lower grades (1 or 2) mean lower recurrence.
- A grade 1 meningioma with a Simpson 1 resection has the lowest risk of recurrence.
- The histological (molecular) grade of the meningioma (grade 1, 2, or 3) also influences recurrence.
- Neurosurgeons commonly reference the Simpson grading scale in discussions about meningioma surgery.
Key Terms & Definitions
- Meningioma — a type of brain tumor arising from the meninges (membranes covering the brain and spinal cord).
- Simpson grading scale — system (grades 1–5) to classify extent of meningioma resection and predict recurrence risk.
- Dura — the outermost membrane covering the brain and spinal cord.
- Coagulation (bipolar) — surgical technique to cauterize tissue, often used to treat the dura after tumor removal.
- Subtotal resection — removal of only part of the tumor.
Action Items / Next Steps
- Memorize the details of each Simpson grade (1–5) for exams and clinical discussion.
- Review differences between meningioma histological grades and their impact on recurrence.
- Prepare for potential questions on grading scales for common neurosurgical tumors.