Brain tumors Flashcards
Infratentorial tumors
o Medulloblastoma o Ependymoma o Cerebellar Astrocytoma (pilocytic) o Brainstem gliomas (DIPG) o AT/RT
Cerebrum tumors
o LGG o HGG o PNET o AT/RT o Ependymoma o CPC/CPP
Sellar tumors
o Craniopharyngioma o LCH (in the stalk) o Germ Cell Tumor o Adenoma/hamartoma o Pilocytic astrocytoma o PNET
Pineal tumors
o Pineoblastoma o GCTs o Pineal cyst o PNET o Astrocytomas
Major post-op issues
Obstructive hydrocephalus with increased ICP is managed with steroids followed shortly by EVD placement.
Pituitary dysfunction can lead to an Addisonian picture – treat urgently with steroids
SIADH is common postop – treat with fluid restriction. Cerebral salt wasting also occurs (they are hypovolemic)
Seizures can be the result of the primary tumor or of disturbances from surgery.
Cerebellar mutism – risk factors include tumors and surgery of the vermis, younger age, female, larger resection area. Occurs in 25% of “eligible” surgeries and not all recover.
List 6 side effects of brain radiation
- Skin toxicity
- Alopecia acutely or subacutely
- Radiation necrosis
- Cerebral edema
- Somnolence syndrome
- Mucositis can occur if radiation volume includes esophagus.
- Ototoxicity can be a long term side effect
- Cataracts occur if the lens is included in the radiation field (risk starts at 10 Gy)
- Retinal toxicity can occur at > 45 Gy
- Vacular complications can occur at any time
prognostic factors in LGG
- Age (younger patients do worse – potentially because of difficulty in treating)
- Histology (fibrillary tumors do worse)
- Extent of resection
o In a COG study, 8 year PFS/OS for GTR was 90%/99%
o 8 year PFS/OS for no GTR was 50%/90% - Underlying syndrome (patients with NF1 do better)
- Location (OPGs do better, patients with diencephalic syndrome potentially do worse)
3 situations do you not need a biopsy?
Dipg
Gct with elevated tumor markers
Nf-1, particularly optic pathway gliomas
Diencephalic syndrome
emaciation, euphoria, emesis
Parinaud Syndrome
Sunsetting eyes, enlarged pupils that are poorly responsive to light, poor eye convergence
what are the tumours found in the optic pathway?
pilocytic astrocytoma
retinoblastoma
what tumours orginate in the spinal cord?
low grade astrocytomas
ependymoma (especially myxopapillary)
AA/GBM
What CNS tumours like to metastasize to the spine?
embryonal tumours, germ cell tumours, ependymoma, astrocytoma (less commonly)
NF1 patients are most commonly associated with which tumour?
optic pathway gliomas
NF2 patients are predisposed to which tumours?
bilateral acoustic neuromas
meningiomas of the brain
spinal cord ependymoma
schwannoma of the dorsal roots of the spinal cord
what CNS tumours are associated in patients with Li-Fraumeni?
choroid plexus carcinomas and GBM
tuberous sclerosis patients are associated with which CNS tumours?
SEGA’s- subependymal giant cell astrocytomas-respond to everolimus
they also can develop hamartomas
patients with Gorlin syndrome are at risk of developing which CNS tumour
medulloblastoma
what WHO grades are for the following gliomas? ----Diffuse astrocytoma —Anaplastic astrocytoma, —Glioblastoma, --Pilocytic astrocytoma —Diffuse midline glioma, H3K27M-mutant
-Diffuse astrocytoma, II —Anaplastic astrocytoma, III —Glioblastoma, IV —Pilocytic astrocytoma I —Diffuse midline glioma, H3K27M-mutant IV
what are unfavourable prognostic features for LGG?
younger age diffuse histology inability for complete resection diencephalic syndrome intracranial HTN at presentation metastatic disease
what are the treatment options for LGG?
in instances of NF1 or asymptomatic can observe
Gross surgical resection can be curative
chemo options are carboplatin/VCR (60weeks) or TPCV-thioguanine, procarbazine, lomustine, VCR (48 weeks)
what is standard treatment for HGG?
attempt best possible resection
all get 54Gy with temozolamide (as a sensitizer)
can consider chemo-Pred/VCR/CCNU for 48wks
name the WHO classification for medulloblastoma
- Medulloblastoma, genetically defined.
- Medulloblastoma, WNT-activated.
- Medulloblastoma, sonic hedgehog (SHH)-activated and TP53-mutant.
- Medulloblastoma, SHH-activated and TP53-wildtype.
- Medulloblastoma, non-WNT/non-SHH.
- Medulloblastoma, group 3.
- Medulloblastoma, group 4.
- Medulloblastoma, histologically defined.
- Medulloblastoma, classic.
- Medulloblastoma, desmoplastic/nodular.
- Medulloblastoma with extensive nodularity.
- Medulloblastoma, large cell/anaplastic.
what hereditary cancer syndromes are associated with medulloblastoma?
Turcotte Syndrome Li-Fraumeni Gorlin Fanconi •Rubinstein-Taybi
when should CSF be obtained from medulloblastoma patient for staging?
CSF done more than 10 days after the original surgery
describe the medulloblastoma risk categories
Avg Risk-no mets, <1.5cm2 residual tumour, greater than 3yrs old
High risk: positive CSF or MRI, >1.5cm2 of residual tumour, large cell anaplastic histology, <3yrs old
describe the 4 molecular subgroups of medulloblastoma
WNT: very good prognosis, seen in older children and adults (10-15%)
SHH: those that aren’t TP53 mutated have a good prognosis. You can see the desmoplastic/nodular histologic subtype
Grp 3: children and infants, VERY frequently metastatic Poor outcome, more common in males
Grp 4:: frequently metatstatic, prognosis intermediate, more common in males
do patients with medulloblastoma get CSI?
yes, all receive CSI as part of standard of care, however those with high risk disease receive 36cGy instead of 23.4cGy
how can you differentiate DIPG from astrocytoma of the brainstem?
DIPG do not enhance on imaging
lesion without exophytic component are DIPG (those that have exophytic are usually LGG)
what genetic subtype of ependymoma is most common in pediatrics
posterior fossa-EPN-PFA usually grade 2 or 3 seen in younger children has a poor prognosis see a gain of chromosome 1q in 25% cases which is a poor prognostic factor
what location is the most common for an ependymoma to present?
fourth ventricle, commonly from the floor of the 4th ventricle
what supratentorial mutation is most common in ependymoma’s?
The largest subset of pediatric supratentorial (ST) ependymomas are characterized by gene fusions involving RELA, a transcriptional factor important in NF-κB pathway activity
what are unfavourable prognostic factors in patients with ependymoma?
molecular profile tumour location younger age subtotal resection anaplastic histology lower doses of radiation
where do germinomas (non-secreting GCT) like to present? Do these tumours require a biopsy?
1) suprasellar region-develop DI, panhypopit
2) Pineal region (Parinaud’s, elevated ICP)
these tumours require a biopsy
what type of GCT does not require a biopsy?
non-germanomatous germ cell tumours are secretory and do not require a biopsy. Either serum or CSF AFB/BHCG are elevated
how are NG-GCT treated?
given neoadjuvant therapy with carbo/etop alternating with ifos/etop for 6 cycles, then receive response based rads-with CSI
Imaging findings of medullo
Posterior fossa
Midline in younger, more lateral in older kids
Contrast enhancing and bright on T2Flair
prognostic findings for HGG
• GTR (hence location)
• Non H3K27M is favourable (3 year survival for mutated tumor <5%)
• IDH1 mutant carries favourable prognosis
• GBM worse than AA (anaplastic astrocytoma, grade 3)
- age (likelihood to radiate)
- MGMT promoter mutations do better
What is the characteristic MRI finding of craniopharyngioma?
- occur in the region of the pituitary gland
o “ccc” = cystic + calcifications = craniopharyngioma
What is the treatment for craniopharyngiomas?
- excision if possible
- 50 Gy reduces risk of recurrence - generally xrt only if residual tumor present
- No established chemo. Intracystic interferon tried.
RF for HGG
p53
Biallelic mismatch repair deficiency
Prior radiotherapy
Treated NG-GCT. Mass growing but markers normal. What is this?
Growing teratoma syndrome
