279. CNS Cancer

Question 1

General

• how are CNS cancers dx?
• sx of CNS tumor? - be SPECIFIC
• what is the most common type of CNS cancer?

Answer 1

dx: MRI with IV contrast (GOLD STD)
- but surgical biopsy/excision is necessary for histo dx

CP
General: HA, N/V
Localized: depend on location - weakness, numbness, gait ataxia, visual changes, language dysfx
HEADACHE: mild onset begins when wake in AM, disappears shortly, then recurs next AM, gradually increases in freq/duration/severity, may worsen with changes in ICP

Most common type: Metastatic disease (lung > breast > melanoma)

Question 2

Glioma

• cell of origin (prevalence of cells in brain)
• two subgroups (fx of cells)
• naming for grade

Answer 2

Origin: neuro-epithelial tissue
Epi: 90% of cells in brain

1. Astrocytoma
   - astrocytes: support brain and SC, component of BBB, create microenviro for neurons
   - stain for GFAP
   i. Pilocytic Astrocytoma (low grade)
   ii. Diffuse Astrocytoma (low grade)
   iii. Anaplastic Astrocytoma (high grade)
   iv. Glioblastoma Multiforme (high grade)
2. Oligodengroglioma

Question 3

Glioblastoma Multiforme

• grade
• cell of origin
• epi, age of onset
• prognosis, tx
• location
• sx
• biopsy

Answer 3

WHO grade IV
origin: astrocytes or their precursors
epi: most common malignant brain tumor of adults, median age 64yo
Prognosis: very poor (16-21 mo)
tx: non-curative: surgery (maximal resection goal to improve sx and optimize chemo/RT = NOT curative AND IS needed for dx), chemo (Temozolomide, causes fatigue), radiation, tumor treating fields (alternating electric fields disrupting mitosis, arrays placed directly on skin near tumor)
location: cerebral hemispheres
sx: high icp, focal neuro sx, seizures (less frequent)
biopsy: pseudo-pallisading necrosis, microvascular proliferation

Question 4

Oligodendroglioma

• cell of origin
• biopsy
• CP
• epi, age of onset
• location
• prognosis/tx
• grade
• genes

Answer 4

Origin: oligodendroglioma
Biopsy: fried egg cells, chicken wire vasculature
CP: Seizures (focal seizure in young adult)
Epi: less common than GBM, median age 41yo
Location: supratentorial, frontal lobes, in white matter but infiltrate more + diffusely, may be calcified
grade: WHO Grade II (low grade) and III (anaplastic)
genes: 1p19q codeletion

tx: maximal surgical resection, chemotx (may see tumor shrinkage, resolution of sx)
Prognosis: 15 year survival, will see transformation to anaplastic oligodendroglioma over time (cause of death in pts)

Question 5

Meningioma

• cell of origin
• grade
• epi, age
• RF (2)
• CP
• imaging findings
• tx/prognosis
• histo

Answer 5

Origin: meningothelial arachnoid cap of meninges
Grade: most benign (Grade I), slow growing tumors that compress brain
Epi: most common benign tumor in adults, median age 64
RF: genetic (NF 2), prior exposure to ionizing radiation
CP: focal seizure, neuro deficits from brain or CN compression
Imaging: diffuse contrast enhancement (outside BBB)

Tx: if asx - follow w/o resection
if sx/size - surgery
Prognosis: most times, tumor NOT cause of mortality

histo: whorled pattern, psamomma bodies

Question 6

Vestibular Schwannoma

• behavior
• eiology: unilateral vs bilateral
• CP
• tx, complications

Answer 6

• slow growing
• unilateral: sporadic
• bilateral: NF-2 (defect on Ch 22 - merlin protein)
• CP: gradual unilateral hearing loss, maybe tinnitus, vague dizziness (rare because slow growth allows vestibular compensation)
• tx: surgery is curative, but high morbidity (hearing loss CN8, facial paralysis CN7, severe persistent HA of unknown cause)

Question 7

CNS Lymphoma

• etiology of primary vs. secondary
• pathogenesis (2 hypotheses)
• CP
• median age, location
• tx

Answer 7

Primary: non-Hodgkin’s Lymphoma (arises w/in and restricted to CNS)
Secondary: mets from systemic disease
Pgen
1. CNS sanctuary (tumor circulates and seeds brain, immunologically privileged = growth)
2. Inflammatory process (lymphocytes traffick into brain due to inflammation and then transform to malignant cells)

Age: 66yo median
location: frontal lobes, corpus callosum, deep periventricular brain structures (can be multifocal or include eye, leptomeningeal - subarachnoid space)
CP: cognitive impairment, behavior change, HA, no B sx

Tx:
Corticosteroids: decrease edema, kill lymphoid cells, causes steroid-resistant recurrence
Induction chemo, consolidation chemo (high dose systemic MTX, RT)
RT risks more cognitive decline

Prognosis: may cure!
3-4mo without tx
30-60mo with chemo alone
12-18mo with RT alone