CNS Flashcards
What are histologic features of astrocytic tumors?
Grade 2: nuclear atypia only
Grade 3: nuclear atypia, focal or dispersed anaplasia, increased mitotic activity
Grade 4: microvascular proliferation, necrosis (and nuclear atypia, increased mitoses, but only the first two are pathognomonic for GBM).
If a tumor is IDH wildtype, it is automatically GBM if one of the following is present:
- TERT promoter mutation
- EGFR amplification
- combined gain of entire chromosome 7 and loss of entire chromosome 10 [+7/-10]
- necrosis
- microvascular proliferation
What are molecular biomarkers in CNS cancers
CDKN2A/B: homozygous deletion in IDH-mutant astrocytoma’s
GBM: automatically GBM if: TERT promoter mutation, EGFR amplification, +7/-10 copy number change
Glioma and GBM systemic therapies:
LGG: adjuvant PCV x 6
AO: PCV x 6
AA: RT -> Adjuvant TMZ 150mg/m2 d1-5 q28d cycles x 12 cycles
GBM: CRT with concurrent TMZ 75mg/m2 EVERY DAY -> adjuvant TMZ 150mg/m2 d1-5 q28d cycles x 6 cycles
Toxicity of WBRT/GBM treatment
ACUTE:
Alopecia (2nd to 3rd week)
Dermatitis
Fatigue
Transient worsening of symp d/t edema (esp 1st 2 wks)
N/V: esp brainstem
Otitis externa
LATE:
Alopecia (hair regrowth, if ever, 3-6m)
Telangectasias
RT necrosis
Diffuse leukoencephalopathy
Cerebral atrophy
Hearing loss
Retinopathy, cataract, visual change
Endocrine abnormality
Vasculopathy
Neurocog: decr new learning ability, short term memory, problem solving skills
2nd malignancy
Pituitary adenoma management
1) management
2) LC with RT
3) what labs to monitor for
GTR -> OBS
If medically inoperable or recurrence not amendable to sx: 50/25 (CTV 0mm duh)
LC: 90%
Most common deficiency after RT: GH: monitor with IGF-1.
Others: TSH, prolactin, cortisol, if a female with amenorrhea then LH and FSH
bitemporal hemaniopsia caused by
If lesion in left occipital what visual field deficit?
1) chiasm
2): right homonymous hemianopsia (right visual field loss)
Hormones produced by pituitary:
1) anterior (6)
2) posterior (2)
1) LSH, FSH, TSH, ACTH, GH, prolactin
2) Oxytocin, ADH
What are the indications for adjuvant radiation in pituitary adenomas/indications for post-op RT
Pituitary:
Non-functional: GTR-> observe. If SRT -> consider XRT on progression (this is benign, do not want 2% risk of 2ndary malignancy, this can be a GBM and the patient can die)
Functional:
XRT if unresectable, medically inoperable.
- IF functional, not controlled by medical management and recurrent after multiple surgeries then do XRT
DOSE: always say 54/30 or 50/25 do not say SRS for these hehe but if you need to know it, it is 15/1 non functional, 20/1 for functional
What is a potentially fatal complication of macroadenoma if untreated
Pituitary apoplexy: due to acute ischemic infarct or hemhorrahge of the pituitary: causes bitemporal hemaniopsia, double vision, and pain
Differential diagnosis for GBM (not including glioma)
Benign: Infection/abscess, AVM –arteriovenous malformation, Foreign body – ie: bullet, Hemorrhage/blood Multiple sclerosis (demyelinating plaque, Radiation necrosis
Malignant: Mets, Ependymoma, Germinoma, Schwannoma (acoustic neuroma), Pituitary adenoma, Primary CNS lymphoma, Meningioma, Choroid Plexus Tumors, Germ Cell Tumors
NOTE: DDX rim enhancing lesion: MAGIC DR:
M: etastasis
A: abscess
G: GBM
I: infarct
C: contusion
D: demyelinating (MS)
R: radiaiton necrosis
What is PCV and what class of chemotherapies
Procarbazine: (alkylating agent)
CCNU: (aka lomustine): alkylating agent
Vincristine: vinca alkyloid
TMZ:also alkylating agent
Question about dilantin:
1) side effects of dilantin:
2) what is the point of a loading dose
What are side effects of dilantin
1) N/V, abdominal pain, liver dysfunction, skin reaction, gingival hypertrophy
2) Achieve therapeutic level more quickly- need to monitor serum pheny level
TMZ class and S/E
Alkylating agent! Thrombocytopenia, fatigue, nausea!!!!
how to stabilize seizure
Lorazepam 4mg IV over 2 minutes (for status epilepticus)
Load with phenytoin and refer to neurology for AED of choice
Start AED (levetiracetam, lamotrigine, topiramate)
3 reasons to do MRI brain 24 hours post op
- To assess for extent of resection (gross total vs subtotal with residual disease)/residual disease
- To assess resolution of previous findings: midline shift, cerebral edema
- To obtain imaging to prevent post-op changes from obscuring radiographic findings
DDx posterior fossa mass (can say for both adult and peds)
BEAM:
brainstem glioma
Ependymoma
Astrocytoma: usually JPA
Medulloblastoma
ALSO: in adults: hemangioblastoma, lymphoma, mets
Benign: cyst, hematoma, abscess, infarct etc.
When do give CSI
1) prophylactically (AKA always even when no visible disease)
2) for visible disease in spine
1) medulloblastoma, PNET
2) Ependymoma (if disseminated), pineal tumors, Germ cell tumors. Also for ALL prophylaxis
Molecular features of oligo, astro
Both IDH mutated
- oligo: 1p19q co-deleted (almost always IDH1 mutated)
- Astro: CDKN2A/b: grade 4; ATRX, p53 mutant
Meningoma genetic conditions
Tuberous sclerosis (give mTOR inhibitor), NF2 (also has bilateral schwannomas, spinal or intracranial meningomas, eye lesions, skin lesions), tuberous sclerosis
OTHER RFs: female, age, ionizing RT
Risk factors for Gliomas and genetic syndromes.
Prior CNS radiation, fam history, genetic syndromes (NF1 and NF2, TS, li fraumeni, turcot)
