Brain Tumours Flashcards
What is a brain tumour?
Overgrowth of tissue Can be benign or malignant Primary or secondary Supratentorial or infratentorial Extrinsic (meninges, bone, blood vessel) or intrinsic
How do brain tumours commonly present?
Progressive neurological deficit - usually contralateral motor weakness
Headache
Seizure
What are the consequences of increased ICP (normal is 5-10 mmHg)?
Headaches
Vomiting
Mental changes
Seizures
Describe the monroe kelly doctrine?
The head is a "rigid closed box" 3 components: Brain (80%) Blood (10%) CSF (10%)
Describe a classical headache assoc with brain tumours
Can occur with/without raised ICP
Worse in morning - wakes them up
Increased with coughing/ learning forward
May be associated with and increase vomiting
Describe the aetiology of a tumour headache
Raised ICP
Invasion/ compression of dura, BVs, periosteum
Diplopia (CN 6)
Difficulty focussing
Cushing’s triad (tonsillar herniation; extreme hypertension, brady)
Psychogenic (stress of loss of functional capacity)
What is the imaging of choice for someone with suspected brain tumour?
MRI
How can tumours of the CNS be classified?
Meninges Neuroepithelial tissue Nerve sheath cells Developmental lesions Sella lesions Germ cells Local extension from adjacent structures Haemopoietic/ lymphomas Mets
What is the commonest type of brain tumour?
Neuroepithelial tissue: Astrocytes - 60% (2/3rd are high grade) Oligodendrocytes Ependymal Neuronal Pineal Embryonic
How can astrocytic tumours be graded?
1; purely benign; pilocytic, pleomorphic xanthoastrocytoma, subependymal giant cell
2; low grade
3; anaplastic
4; GBM
How are tumours graded in terms of pathology?
Microvascular proliferation
Nuclear pleomorphism
Excess mitoses
Angiogenesis
Describe grade 1 astrocytoma’s
Truly benign Slow growing Common in children/ young adults Commonly cause increased ICP Tx; surgery (curative)
T1 MRI scan used - you can tell as the CSF is black, contrast used (only use contrast in T1 weighted MRI images)
Describe grade 2 astrocytoma’s
Fibrillary, gemistocytic, protoplasmic
Show hyper cellularity, pleomorphism, vascular proliferation, necrosis
Predilection; temporal lobe
Presentation; seizures
Describe the poor prognostic factors associated with low grade astrocytoma’s
Age >50 Focal deficit Short duration of symptoms Raised ICP Altered consciousness Enhancement on contrast studies
Describe the tx of grade 2 astrocytoma’s
Surgery +/- radiation, chemo, radio/chemo combo
Surgical biopsy; stereotactic vs open
Seizure control, herniation, CSF obstruction, cytoreduction
Describe a landmark trial in the treatment of grade 2 astrocytoma’s
N=251 with a follow up of 11.9 years
55% had died
Patients who received radio + chemo (PCV) has an overall longer survival (13.3 vs 7.8 years)
Rate of progression free survival at 10 years was 51% compared to 21% in group that received radio alone
Describe the malignant astrocytoma’s
Grade 3; arise de novo. Median survival 2 yrs
Grade 4; most common primary brain tumour. Median survival 14-15 months
Spread; white matter tracking/ CSF pathways
Multiple gliomas = NF, TS, PML
What is the treatment for malignant astrocytoma’s
Non curative surgery - survival quality
Surgery; cytoreduction without causing a neurological deficit (reduce mass effect)
Post op radio; external beam therapy
Stupp protocol; Sx + Rt + TMZ (temozolomide)
If MGMT methylated tumour - increased life expectancy
When is radiotherapy utilized in brain tumours?
Always after malignant tumours
Low grade; incomplete removal, malignant degeneration
Benign astrocytoma’s; only if recurrence/ progression not amenable to surgery
Are there any novel therapies for treatment of brain tumours currently in phase 3 of clinical trials?
Yes; TTFs (electrical current) which prevents tumour mitoses
Increased survival of 2 months
Describe meningiomas
Originate from arachnoid cap cells
Extra-axial
20% of intracranial neoplasms
Majority are asymptomatic
Assoc with breast cancer and NF 2 (22q)
Associated with bone = meningioma en plaque
90% are benign and slow growing
Classification; classic, angioblastic, atypical, malignant
Symptoms of meningioma
Headache
Skull base; CN neuropathy
Regional anatomical disturbance
Describe grade 3 meningiomas
Clear cell Choroid Rhabdoid Papillary Radiation induced meningioma (after childhood leukaemia - typically in midline)
How can meningiomas be assessed preoperatively?
CT; homogenous (lights up like a lightbulb), densely enhancing, oedema, hyperostosis
MRI; dural tail, patency of dural sinuses
Angio +/- embolization; external carotid artery feeders, occlusion of sagittal sinus
What is the treatment for a meningioma?
Small; expectant Periop embolization Surgery Radiotherapy Recurrence; depends on grade and extent of resection Outcome; 5 yr survival is 90%
Describe nerve sheath tumours
Schwannomas
Neurofibromas
Malignant peripheral nerve sheath tumours
Describe vestibular schwannomas
Sensorineural hearing loss Tinnitus Disequilibrium CN palsies; 5, 7, 8 Brainstem function Hydrocephalus
What is the treatment for vestibular schwannomas
Expectant - perform audiometry, radiographic evaluation. 1/3rd won’t grow
Hydrocephalus management - shunt insertion
Radiation - stereotactic radiosurgery
Surgery
What needs to be analysed post op after surgery for vestibular schwannoma
Facial nerve palsy (grading system)
Corneal reflex (ulcer, sympathetic ophthalmoplegia)
Nystagmus
Abnormal eye movement
What blood tests should be performed in children with midline tumour on MRI scanning?
AFP
b-HCG
LDH
If neg; needs a biopsy and CSF sample via ETV
Germ cells are chemo and radio sensitive
How can hydrocephalus be treated?
VP shunt
50% revision rate within 10 years
Describe the pituitary gland tumours
Px; bitemporal hemianopia, HA, endocrine abnormalities
Ix; prolactinoma (cabergoline CURES)
GH/ IGF-1; acromegaly can kill due to HOCM; surgery and somatostatin analogues
Cortisol (test in morning); Cushing’s disease can be fatal
TSH, fT4, fT3
FSH, LH (high only after menopause)
VA and visual fields = indication for surgery
Describe the signs of panhypopituitarism
Pallor Fine wrinkling of skin Absent axillary hair Face puffy Expressionless
Tx; GS first, then LF/FSH, then TSH, then ACTH then prolactin
What is decorin?
Inhibits primary breast cancer growth and distant mets in a mouse model
Shrinks tumour in animal models of GBM
