1. Clayton Wiley, M.D., PhD

2. Question 1
Clinical history: 40-year-old female with complaint of low back pain radiating to the lower extremities. Describe the abnormal spinal MRI findings?

3. Sag T2

4. Sag T1+C

5. Question 2
What are your differential diagnoses based on the patients’ age and the radiological findings?

6. Answer
Ependymoma
Subependymoma
Astrocytoma
Paraganglioma
Infection?

7. Question 3
The neurosurgeon performs a L1-2 decompressive laminectomy with resection of the focally encapsulated mass within the cauda equina and/or conus medullaris, and requested an intraoperative consultation. Describe the microscopic findings on this frozen section slide? Click here to view slide.

8. Question 5
The permanent section has returned from histology. Describe the microscopic findings on this H&E slide? Click here to view slide.

9. Question 6
What additional immunohistochemical studies would a neuropathologist need to confirm the final diagnosis?

10. Answer
GFAP
EMA
Ki-67

11. Question 7
What do you see on this GFAP immunostain slide? Click here to view slide.

12. Question 9
What do you see on this Ki-67 (MIB-1) immunostain slide? Click here to view slide.

13. Question 10
What is your final diagnosis in this case?

14. Answer
Myxopapillary Ependymoma

15. Question 11
What is the corresponding WHO grade of this lesion?

16. Answer
WHO Grade 1