Tumors of the CNS Flashcards
How do tumors of the CNS usually present as?
- PROGRESSIVE neurological deficit (68%)
- HEADACHE (54%)
- motor weakness
- Seizures
What is an eventual consequence of raised ICP?
- Mass in skull (rigid closed box) may BLOCK csf flow ==> HYDROCEPHALUS
- Hemorrhage
(vomiting/mental changes/ seizures)
Swollen brain may _______
herniate (uncal/tonsillar/subfalcine/central herniation)
Why may headache arise from a tumor?
- raised ICP
- compression of DURA, blood vessels, periosteum
- 2ry to DIPLOPIA (II,IV,VI; INO)
- 2ry to diff. focusing
- extreme hypertension (CUshing’s Triad)
- psychogenic
Tumor in the temporal lobe may result in ?
- alterations in behaviour
- memory
- hearing
- vision
- emotion
Left hemisphere of the brain is responsible for?
- speech, MOTOR, sensory fxn
What concepts is the right hemisphere resp. for?
- abstract concepts
How may raised ICP trigger Cushing’s triad?
- raised ICP may reduce cerebral blood flow
- CUSHING’s triad is in response to overcome the raised ICP
- incl. Hypertension/ bradycardia/ bradypnoea
What are glial tumors?
How are the Astrocytic tumors graded?
Tumors that arise from astrocytes or oligodendrocytes
- 3-tier system of astrocytic tumors :
1. Astrocytomas
- Anaplastic astrocytoma
- Glioblastoma Multiforme
Tumor grading is based on 4 fts. What are they?
- endothelial proliferation
- cellular PLEOMORPHISM
- MITOSES
- presence of NECROSIS
Can low grade astrocytic tumors become aggressive?
- YES
- they grow slowly but hve the propensity to become malignant over time
So best way to treat a glioma?
- SURGICAL RESECTION!
Curative
Name a grade 1 astrocytoma and who are victim to it?
- PILOCYTIC Astrocytoma
- —seen in children and young adults
Where may the pilocytic astrocytoma be found?
- optic nerve
- cerebellum
- hypothalamus
- brainstem
WHere do low grade astrocytomas form?
- temporal lobe
- posterior frontal
- anterior parietal
What are the poor prognostic factors for low grade astrocytomas?
- > 50y.o
- focal deficit
- SHORT duration of symtpoms
- raised ICP
- ALTERED CONSCIOUS
- enhancement on CT
Name a grade II astrocytoma.
Fibrillary Astrocytoma
How is fibrillary astrocytoma treated?
- surgically +/- radiation/ chemo/ combinat.
What are the poor prognosis factors in Gr. II astrocytoma?
- > 45y.o
- large tumor (>6cm)
- incomplete resection
Name a gr.III astrocytoma and its median survival?
- Anaplastic astrocytoma
- ~2 years
What grade is Glioblastoma Multiforme? What is the median survival rate?
- GR.IV
- most common PRIMARY tumor
- — <1yr
How does the glioblastoma multiforme spread?
- via WHITE matter
- CSF pathways
Since a surgical resection (alone) of the glioblastoma multiforme is not as effective; how is the high grade astrocytoma managed?
STUPP protocol
- surgical resection
- radiotherapy
- temozolomide (adjuvant therapy)
- —improves survival to 14 months
Role of DVLA for a pt just recived brain surgery? -
- PT TO INFORM DVLA of driving (not safe post-op d.t seizure risk)
- OR if left with significant homonynous visual field defect
What forms of chemo is available?
- Temozolomide
- PCV (procarbazine/ CCNU- Lomustine/ Vincristine)
- carmustine wafers
How effective is radiotherapy?
- MALIGNANT degeneration in LOW grade astrocytomas with or without surgery or done if incomplete resection was performed
- given to BENIGN astrocytomas if recurrence is NOT amenable to surgery
What are the S.E of RT?
- drops IQ by 10
- skin and hair loss
- tired
Explain in 3 steps how immunotherapy works.
- tumor tissue is harvested FTER SURGERY (made separate into Ag)
- in lab dish Ags are mixed with dendritic cells
- mixture injected into pts skin
60% of glial tumors are Astrocytomas.
What is the 20% of glial tumors?
- Oligodendroglial tumors
Where are (and in whom) Oligodendroglial tumors usually found in?
Its primary presentation?
frontal lobes
- adults 25-45 y.o
- Seizures
How to distinguish oligodendrogial tumors from astrocytomas?
- cysts
- peritumoral hemorrhage
- calcification (peripheral)
What is the grading of oligodendroglial tumors?
- LOW gr.
- anaplastic/astrocytic component
How to rx oligodendrogliomas?
- chemosensitive: PCV/Lomustine/ Vincristine
- Surgery+ Chemo
- to decr. seizures: RT
- –RT+ PCV doubles survival
Median survival low gr. oligodendroglioma?
10 yrs
What are red flags for brain tumors?
- headaches that WAKE you up +/- vomiting
- new neuro deficits
- seizures
- tiptoeing, ataxia
- vomiting with HA in kids
What support should the pt be made aware of>
- Macmillan nursing
- family support
What are the symptoms of meningiomas?
- usually asymptomatic
- headaches
- at skull base? = CN neuropathies
- regional anatomical disturbance
Where are meningiomas found?
- parasagittal
- convexity
- sphenoid
- intraventricular
What are the diff types of meningiomas>
- classic
- angioblastic
- atypical (2%)
- malignant (5%)
What are the aggressive types of meningiomas?
- clear cell
- choroid
- rhabdoid
- papillary
- radiation induced meningiomas (hx of childhood leukemia/ in MIDLINE)
What is seen on CT for meningiomas?
- homogenous (densely enhancing)
- EDEMA
- hyperostosis/ skull blistering (thickening of skull)
What is seen on MRI meningiomas?
- DURAL tail (d.t attachment of meningioma to dura)
- patency of dural sinuses
What additional vascular investigation is performed for meningiomas?
- angiography +/- embolisation
EXT. carotid feeders/ sagittal sinus occlusion
What is the treatment of meningiomas?
- pre-operative embolisation
- surgery
- rt
- 5yr survival for 90%
Name nerve sheath tumors.
- schwannomas
- neurofibromas
- malignant peripheral nerve sheath tumors (1%)
What is a vestibular sschwannomas? And its symptoms?
- acoustic neuroma arising from CN 8
> hearing LOSS
> Tinnitus
> dysequilibrium
What nerves can also be grossly affected by the acoustic neuromas?
CNs 5, 7, 8
—consequently leading to brainstem fxn and hydrocephalus
How to rx acoustic neuroma?
- audiometry/audiologic
(radiographic evaluation)
——hydrocephalus management+ RT+ surgery
—–50% managed surgically (rapid loss of hearing w/ or w/o surgery)
25% managed medically (periodic neuro exam, hearing aid, periodic MRI)
If the AN is <3cm big, what is usually done to manage it?
How effective is it?
- GAMMA knife procedure (doesn’t require the opening of the skull)
- hearing still declines over SEVRAL years
- vestibular fxn worsens a lot in first 6 months, then stabilizes
Risk of AN ?
rare for malignant transformation
- but decline in hearing is inevitable
(slower with Gamma Knife)
75% increase in SIZE over 2 years
Post-op complications of Acoustic neuromas?
- facial nerve palsy
- loss of corneal reflex
- nystagmus
- abnormal eye movements
Where are intracranial germ cell tumors usually found?
Pineal gland and pituitary gland
What are the general fts of Germ cell tumors?
90% affect those YOUNGER than 20 y.o
- Males
Medium through which GC tumors metastasize?
- via CSF
Most common CNS GC tumor?
GERMINOMAS
radiosensitive
Best CT imaging in which GC tumors are best visible?
ISO- or HYPERdense
What are the 2 chemical substances GC tumors produce and can be used as a tumor marker?
AFP
Beta-HCG
LDH
(check with ANY MIDLINE tumor in child)
Name non-germinomatous tumors.
- teratoma
- yolk sac tumor
choriocarcinoma
embyronal carcinoma
——all of which are LESS radiosensitive
Which GC tumor is produces AFP?
yolk sac tumors
and teratomas
Which GC tumor produces b-hcg?
Choriocarcinoma
Which GC tumor produces Placental alkaline phosphatase?
germinomas
choriocarcinoma
yolk sac
What helps treat hydrocephalus?
Endoscopic third ventriculostomy (ETV +/- biopsy()
Ventriculoperitoneal shunt
What does pituitary tumors cause?
- bitemporal hemianopia
- HA
- endocirne abnormality
- Cushing’s
- Acromegaly
What to expect post-op of pituitary tumors?
HYPOPITUITARISM:
- pallor, yellowish tinge skin (reduced MSH)
- fine wrinkling of skin
- absent of AXILLARY hair
- puffy face and hypomimia
- ——GH is lost first; FHS and LH next (amenorrhea); then TSH, ACTH and PROLACTIN
- —-diabetes insipidus is COMMON post-op
How to identify the tumor is a GLIOBLASTOMA?
- expresses GFAP . . . - Seen in those >65y.o
How does a Glioblastoma classically appear on CT?
crosses the corpus callosum
repping a buterfly on CT
Prior exposure to radiation to the head, predisposes the patient to what exactly?
- MENINGIOMA
Parasagittal meningioma presents as?
- ACA stroke
- hemiparesis (Lower limb)
Purpose of angigraphy +/- embolisation before surgical resection of meningioma?
- meningiomas are usually quite VASCULAR
- angiography allows us to identify if it is a hypervascular tumor
Which brain tumor is said to be estrogen AND progesterone sensitive and often ARISES from the background of pregnancy?
MENINGIOMAS
Pituitary tumors may result in excessive release of various hormones. What risk does this hold?
- GH and IGF-1= ACROMEGALY and death from HOCM
2. Cortisol excess also FATA;
