Brain Tumours Flashcards
Causes of raised ICP? [4]
Localised (Space Occupying) Lesions
- Haemorrhage or haematoma
- Tumour
- Abscess
Also Oedema post trauma
Types of herniation due to raised ICP? [3]
Internal Shift or Herniation:
- Right-left e.g. subfalcine herniation (cingulate gyrus herniates under falx)
- Uncal Herniation (cerebrum moves down over tentorium)
- Coning (Cerebellum, mainly tonsils, moves into foramen magnum)
What happens to tissue around a tumour? [1]
Ischaemia
Early symptom of a raising ICP via 2 mechanisms [3]
Morning Headaches and vomiting from cortex/brainstem compression
Papilloedema & Visual Disturbance from pressure on optic nerve
What other signs appear as ICP increases? [5]
- Pupillary Dilation from stretch on III
- 6th nerve palsy
- Focal Neurological Deficits
- Falling GCS from pressure on Cortex/brainstem
- Brain Stem Death from coning
Intracranial tumours can be divided into 3 major categories?
- Primary CNS tumours
- Secondary (Metastatic) CNS tumours
- Extra-axial tumors CNS
Types of intra-axial tumours [4]
Gliomas
Ependymomas
Medulloblastoma
CNS lymphoma
What cancers commonly metastasise to the brain? [5]
- Breast
- Lung
- Kidney
- Colon
- Melanoma
Where anatomically in the brain would you find tumours in adults vs in children?
Adults - Above Tentorium
Children - Mainly below Tentorium
Astrocytoma = Glioma
Infiltrative tumours from glial cells
Low grade vs High grade
What difference in demographic are there?
Low grade include grade 1-2 astrocytomas
* Young adult and children
High grade include grade 3-4 astrocytomas
* Present in older adults in 4th-5th decades of life
What cell do glioblastomas and astrocytomas originate from?
What low grade glioma is benign? [1]
Both from Astrocytes
Low grade pilocytic astrocytomas are malignant while low grade gliomas are generally pre-malignant
Glioblastoma vs astrocytoma
What are similarities [2]
Whats the difference [3]
Both originate from astrocytes & are malignant
Astrocytomas:
- Bland mostly normal cells
- Low Grade tumour
- Grows very slowly
Glioblastoma
- Cellularly Atypical (multiple or irregular nuclei)
- Grows very quickly
- Grade 4 astrocytoma
- Shows necrosis microscopically
What does a medulloblastoma originate from?
Primitive Neuroectoderm (primitive Neural cells)
Describe a medulloblastoma?
- Forms sheets of small undifferentiated cells
- Malignant
Medulloblastoma
Which age group usually affected?
Arising from what cell?
Presentation
Location of tumour
Treatment
20% of all childhood CNS tumour
Arise from granule cell progenitors
5% are inherited or genetic related
Present with headache, ataxia, signs of brainstem involvement
Usually seen in posterior fossa in MRI
Tx: surgery + craniospinal irradiation, chemo
Meningioma
Epidemiology
Arise from what cells
Location
Classification: name 3 grades
Incidence increases with age, women, NF2, hx of cranial irradiation therapy
Arise from dura mater, neoplastic meningothelial cells
Located over cranial convexities, adjacent to sagittal sinus, skull base, spinal cord dorsum.
Grade 1: benign
Grade 2: atypical
Grade 3: Malignant
Meningioma
Presentation
Appearance on MRI
Mx
Presentation: headaches, seizures, focal neurologic deficits
Imaging: partially calcified, densely enhancing extra-axial tumour arising from dura, with dural tail.
Mx: complete resection usually results in no recurrence, +/- stereotactic radiotherapy
What do we call the calcifications of a meningioma seen under microscope?
Psammoma body formation
Give one major example of a schwannoma? Location? [2]
VIII nerve Schwannoma (Acoustic Neuroma)
Generally at angle of Pons & Cerebellum
Schwannoma
Arise from nerve roots so can be cranial nerve or spinal nerve.
Most known is the vestibular schwannoma/acoustic neuroma assoc with NF2. NF1 assoc with schwannoma in spinal nerve roots.
Presenting with unilateral symptoms, deafness, dizziness, tinnitus.
Mx: surgery or SRS
What does a pituitary adenoma do? [2]
- Impinge on optic chiasm
- Dysregulation of pituitary hormone secretion
What makes up a CNS lymphoma? [1]
Diffuse Large B-cell lymphoma
Consequences of haemangioblastoma? [2]
Space occupying and may bleed
What makes up most secondary tumours in the brain?
Carcinomas
Clinical Presentation of Intracranial Tumours? [4]
- Symptoms/signs of raised ICP
- Focal Neurological Deficits
- Seizures (in lesions of cerebral cortex, think tumour in an adult onset seizure)
- CSF obstruction (Hydrocephalus)
Investigation of intra-axial tumours
Cranial MRI is ppreferred
CT for patients incompatible with MRI
Malignant - will enhance with gadolinium
Low grade gliomas - wont enhance
fMRI for surgical planning
PET
MR perfusion
Cancer markers - BHCG, HCG
What are the approaches of Intracranial tumour management? [3]
- Diagnosis of benign vs malignant
- Improve quality of life (reducing symptoms and neurological deficits)
- Prolonging life expectancy
What treatments are available for Intracranial Tumours?
Medical [5]
Surgical [2]
- Chemo/radiotherapy
- Corticosteroids (reduces ICP from oedema)
- Anti-epileptics to prevent seizures
- Analgesia
- Anti-emetics
Surgery
- Either as complete resection
- Or debulking to reduce symptoms/ICP
Meningioma management
- If small and asymptomatic, incidental finding, just monitor with serial MRI.
- Surgical resection for larger lesions and symptomatic. But needs to be complete resection otherwise it will recur.
- Irresectable tumours will go for stereotactic radiosurgery
Prognosis for Gliomas: astrocytoma vs glioblastoma multiformes [2]
Astrocytomas have a longer life expectancy which higher rate of cure, grade 1 is potentially curable.
Glioblastoma Multiformes have a 1yr survival avg.
Extra-axial brain tumours types [5]
- Meningioma
- Schwannoma/Neurofibroma
- Pituitary adenoma
- Lymphoma
- Haemanioblastoma (Capillaries)
Diffuse low grade astrocytoma Epidemiology Location [2] Presentation [3] Imaging [2] What can you see?
Young adults
Location: frontal region, subcortical white matter
Presentation: seizures, headache, very slow progression of neurological deficits
Imaging:
- CT - well circumscribed non enhancing hypodense or isodense lesion
- T2 MRI showing surrounding area of edema
High grade astrocytoma Epidemiology [3] Can originate from \_\_\_\_ [2] Prognosis Location [3] Presentation [3] Progression [1]
Adults, 40-60 M>F
De-novo or evolve from low-grade glioma
Poor prognosis
Location: frontal and temporal lobes, basal ganglia
Presentation: seizures, headache, slowly progressive neurological deficits
Progression over weeks (quicker than low grade)
What tumor can infiltrate along white matter tracts and cross corpus callosum? Whats the name of this sign on imaging?
High grade astrocytoma can show a butterfly lesion
Gliomas: High grade astrocytoma
Imaging:
What will CT show? [3]
Management [2]
Central hypodense area of necrosis [1] surrounded by thick enhancing rim [1] (center is necrotic due to cancer outgrowing its blood supply) + surrounding edema [1]
Chemo radiotherapy - survival 14m
Surgery not cure as recurrence is high
Gliomas: Oligodendroglioma Mean age of onset [1] Location [1] Presentation [3] Imaging CT [3] - would you see hemorrhage and edema in CT scan of these patients?
Mean age of onset 40y
Location: superficially in frontal lobe
Presentation: seizures, headache, slowly prog neurological deficits
Imaging CT
- Well circumscribed, hypodense lesions [1] with heavy calcification [1] , cystic degeneration [1], hemorrhage and edema uncommon
Types of presentations of brain tumours [7] depending on location
Cerebral Cerebellar Brainstem Frontal Parietal Temporal Occipital
Cerebral tumor presentation [8]
Headache Vomiting unrelated to food intake Changes in visual fields and acuity Hemiparesis, hemiplegia Hypokinesia Decreased tactile discrimination Seizures Changes in personality or behaviour
Brain stem tumor presentation [7]
Hearing loss - acoustic neuroma
Facial pain, weakness
Dysphagia, decreased gag reflex
Nystagmus
Hoarseness
Ataxia
Dysarthria
Frontal lobe tumor presentation [8]
Headache
Inappropriate behaviour
Personality changes
Inability to concentrate
Impaired judgement
Memory loss
Expressive aphasia
Motor dysfunction
Parietal lobe tumor presentation [3]
Sensory deficits - paresthesia
Visual field deficits
Dyspraxia
What is dyspraxia
Partial loss of ability to co-ordinate and perform skilled purposeful movements and gestures with normal accuracy
Occipital lobe tumor - major symptom [3]
- contralateral visual field defects
- palinopsia (persisting images once object has left field of view)
- polyopia (multiple images seen)
Other than tumors what are other space occupying lesions [4]
- Aneurysm
- Chronic subdural haematoma
- Granuloma
- Cyst
Third Ventricle Colloid Cyst
What are they
Onset
Management
- Congenital cysts
- present in adulthood
Mx is excision or ventriculoperitoneal shunting
Third Ventricle Colloid Cyst
Presentation [7]
- amnesia
- positional headache
- obtundation (blunted consciousness)
- dim vision
- blunted paresthesiae
- weak legs
- drop attacks
Management of space occupying lesions
Benign vs malignant
• Benign: surgical excision unless inaccessible
• Malignant:
o Surgical excision (margins are unclear) for tissue dx, debulking before RT and carmustine wafer insertion
o Adjuvant chemo-radiotherapy (or as sole therapy if inoperable)
Management of space occupying lesions
Seizure only when there has been a seizure beforehand
Cerebral edema [2]
- Seizure prophylaxis: LEVETIRACEM 500mg BD IV/oral no difference
* Cerebral oedema: DEXAMETHASONE (MANNITOL if ICP rapidly rises)
Management of raised ICP [11]
ABCDE
Hypotension correction maintain MAP >90mmHg
Positioning elevate to 30-40
Full sedation and paralysis to reduce brain metabolic activity
Hyperventilation
Osmotic agents
Fluid restriction <1.5l/d
Monitoring neuro obs, consider ICP bolt
Correct electrolyte abnormalities
Surgery: craniotomy or extra-ventricular drain
When can you use dexamethasone in raised ICP?
IV DEXAMETHASONE ONLY IF oedema surrounding tumour
CNS lymphoma
Immunocompetent vs immunocompromised patients
Presentation
Ix
In immunocompetence: DLBCL
In immunocompromised: HIV, organ transplant
Presentation: neuropsychiatric symptoms, raised ICP sign, seizures
Immunocompetent - solitary lesion
Ix: stereotactic bx
Withhold steroids in CNS lymphoma before obtaining biopsy as it melts away lymphoma and bx may not yield anything
CNS lymphoma
Management
- responsive to steroids, chemo and radiotherapy
- high dose methotrexate
- radiotherapy assoc with neurotoxicity
- 50% recurrence
- In immunocompromised: think about ddx like toxoplasmosis, investigations like CSF, EBV, brain PET will help