Brain tumours Flashcards
Brain tumours can be either malignant or benign. True/false?
True
Brain tumours range from benign (e.g., meningiomas) to highly malignant (e.g., glioblastomas)
Can brain tumours be asymptomatic?
Yes
particularly when they are small. As they grow, they present with progressive focal neurological symptoms depending on the location of the lesion.
How do brain tumour symptoms typically present?
Often presents with symptoms and signs of raised intracranial pressure (intracranial hypertension).
A growing tumour takes up room within the skull, leaving less space for the other contents (such as the cerebrospinal fluid), causing a rise in the pressure within the intracranial space.
What is typical presentation for a tumour within the frontal lobe?
Unusual change in personality and behaviour.
The frontal lobe is responsible for personality and higher-level decision-making.
What are causes of increased pressure in the intracranial space?
Brain tumours
Intracranial haemorrhage
Idiopathic intracranial hypertension
Abscesses or infection
For patients presenting with a headache, what are features that could indicate intracranial hypertension?
Constant headache
Nocturnal (occurring at night)
Worse on waking
Worse on coughing, straining or bending forward
Vomiting
Papilloedema on fundoscopy
What are additional features that could be present with raised intracranial hypertension?
Altered mental state
Visual field defects
Seizures (particularly partial seizures)
Unilateral ptosis (drooping upper eyelid)
Third and sixth nerve palsies
What is a crucial fundoscopy finding in patients with raised ICP?
Papilloedema
What is papilloedema?
Refers to swelling of the optic disc secondary to raised intracranial pressure.
Papill- refers to a small, rounded, raised area (the optic disc) and -oedema refers to the swelling.
How does papilloedema cause the optic disc to bulge forward?
The sheath around the optic nerve is connected with the subarachnoid space.
The raised cerebrospinal fluid (CSF) pressure flows into the optic nerve sheath, increasing the pressure around the optic nerve behind the optic disc causing the optic disc to bulge forward.
How does papilloedema appear on fundoscopy?
Blurring of the optic disc margin
Elevated optic disc (look for the way the retinal vessels flow across the disc to see the elevation)
Loss of venous pulsation
Engorged retinal veins
Haemorrhages around the optic disc
Paton’s lines, which are creases or folds in the retina around the optic disc
What are gliomas?
Tumours of the glial cells in the brain or spinal cord. Glial cells surround and support the neurones.
3 main types of glial cells?
Astrocytes
Ependymal cells
Oligodendrocytes
Function of astrocytes?
Makes up the majority of cells in the human central nervous system (CNS)
Main function is forming the blood - brain barrier (divides systemic and brain circulation, regulating concentrations of important ions in the intracellular fluid and synthesis / breakdown of neurotransmitters)
Function of ependymal cells?
Controlling the production and flow of cerebrospinal fluid (CSF), brain metabolism, and waste clearance.
Function of oligodendrocytes?
They create the myelin sheath around neuron axons, which allows for faster and more efficient communication between neurons.
What is the difference between oligodendrocytes and schwann cells?
Both these cells have the same function however oligodendrocytes operate in the CNS whilst schwann cells operate in the PNS.
What are the main 3 glioma types from most to least malignant?
Astrocytoma (the most common and aggressive form is glioblastoma)
Oligodendroglioma
Ependymoma
What are meningiomas?
Tumours growing from the cells of the meninges. They are usually benign.
However, they take up space, and this “mass effect” can lead to raised intracranial pressure and neurological symptoms.
What cancers often spread to the brain?
The cancers that most often spread to the brain are:
Lung
Breast
Renal cell carcinoma
Melanoma
Pituitary tumours are usually benign however can still result in clinical issues, how is this?
If they grow large enough, they can press on the optic chiasm, causing a visual field defect called bitemporal hemianopia, with loss of the outer half of the visual fields in both eyes.
Pituitary tumours can grow large enough and can also cause hormone deficiencies or excessive release of hormones, what can this lead to?
Acromegaly (excessive growth hormone)
Hyperprolactinaemia (excessive prolactin)
Cushing’s disease (excessive ACTH and cortisol)
Thyrotoxicosis (excessive TSH and thyroid hormone)
How can pituitary tumours be managed?
Trans-sphenoidal surgery (through the nose and sphenoid bone)
Radiotherapy
Dopamine receptor agonists (e.g. bromocriptine) to block excess prolactin and can also be used to block excess growth hormone
Somatostatin analogues (e.g. octreotide) to block excess growth
hormone
What are acoustic neuromas?
Benign tumours of the Schwann cells that surround the auditory nerve (vestibulocochlear nerve) that innervates the inner ear.
Schwann cells provide the myelin sheath around neurones of the peripheral nervous system.
What is another name for acoustic neuroma?
Vestibular schwannoma
Usually acoustic neuromas are unilateral. What condition is associated with bilateral acoustic neuromas?
Neurofibromatosis type 2 (NF2)
Typical presentation for acoustic neuromas?
Typical patient is a 40-60 year old presenting with a gradual onset of:
Unilateral sensorineural hearing loss (often the first symptom)
Unilateral tinnitus
Dizziness or imbalance
Sensation of fullness in the ear
Facial nerve palsy (if the tumour grows large enough to compress the facial nerve)
What are management options for acoustic neuromas?
Conservative management with monitoring may be used if there are no symptoms or treatment is inappropriate
Surgery to remove the tumour (partial or total removal)
Radiotherapy to reduce the growth
What is the first line imaging examination for a suspected brain tumour?
MRI scan of the brain
How can biopsy be used in treatment of brain tumour?
Biopsy gives the definitive histological diagnosis, usually obtained during surgery to remove the tumour.
Management of brain tumour is dependant on type and grade, guided by MDT. What are the main options?
Surgery
Chemotherapy
Radiotherapy
Palliative care
What type of brain tumour has a “fried egg” appearance when viewed under microscopy?
Oligodendrocytes
What is the most common type of glioma?
Astrocytoma
What are the 4 main astrocytoma classifications?
Grade 1 - Pilocytic astrocytoma
Grade 2 - Low grade astrocytoma
Grade 3 - Anaplastic astrocytoma
Grade 4 - Glioblastoma
Grade 1 is circumscript (limited/confined) whereas grades 2-4 age diffuse.
