CNS

Question 1

CNS tumors - grading

Answer 1

Oligodendroma
Often grade II-III

Astrocytoma
Often grade II-III
Types: Low-grade (Grade I), diffuse (Grade II), anaplastic (Grade III)

Glioblastoma
Grade IV

Question 2

Mutations in gliomas

Answer 2

Oligodendroma
Often grade II-III
Notable mutations: IDH better prognosis, 1p/19q co-deletion better prognosis
Histology: “fried egg” appearance
Imaging: Bright on flair, no contrast enhancement

Astrocytoma
Often grade II-III
Notable mutations: IDH better prognosis, ATRX
Types: Low-grade (Grade I), diffuse (Grade II), anaplastic (Grade III)

Glioblastoma
Grade IV
Notable mutations: IDH better prognosis, MGMT methylation better prognosis (get TMZ definitely; still get if unmethylated but may not do as well)
Histology: Necrosis, high mitotic activity, vascular proliferation
Imaging: ”butterfly” pattern; ring enhancement

Question 3

Treatment GBM (grade IV glioma)

Answer 3

Surgery –> TMZ + RT concurrent –> 6 cycles adjuvant TMZ

Elderly – 40 Gy in 15 fx + TMZ

Question 4

Treatment grade 1-III Gliomas

Answer 4

Grade 1 –> surgery

Grade 2/3 –> surgery +/-adjuvant chemoRT if high risk (age > 40 or NOT total resection)

Grade 3 –> chemoRT

Chemo = PCV (procarbazine, lomustine, vincristine) or TMZ

Question 5

Treatment meningioma

Answer 5

Observe if small (<3 cm)
Surgical resection
Consider adjuvant RT
No role for chemo

Question 6

Histology for CNS lymphoma

Answer 6

Histology: CD20+, BCL6+, MUM1+ (activated non-GC)