Brain tumours

Question 1

Brain tumours can be either malignant or benign. True/false?

Answer 1

True

Brain tumours range from benign (e.g., meningiomas) to highly malignant (e.g., glioblastomas)

Question 2

Can brain tumours be asymptomatic?

Answer 2

Yes

particularly when they are small. As they grow, they present with progressive focal neurological symptoms depending on the location of the lesion.

Question 3

How do brain tumour symptoms typically present?

Answer 3

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.

Question 4

What is typical presentation for a tumour within the frontal lobe?

Answer 4

Unusual change in personality and behaviour.

The frontal lobe is responsible for personality and higher-level decision-making.

Question 5

What are causes of increased pressure in the intracranial space?

Answer 5

Brain tumours

Intracranial haemorrhage

Idiopathic intracranial hypertension

Abscesses or infection

Question 6

For patients presenting with a headache, what are features that could indicate intracranial hypertension?

Answer 6

Constant headache

Nocturnal (occurring at night)

Worse on waking

Worse on coughing, straining or bending forward

Vomiting

Papilloedema on fundoscopy

Question 7

What are additional features that could be present with raised intracranial hypertension?

Answer 7

Altered mental state

Visual field defects

Seizures (particularly partial seizures)

Unilateral ptosis (drooping upper eyelid)

Third and sixth nerve palsies

Question 8

What is a crucial fundoscopy finding in patients with raised ICP?

Answer 8

Papilloedema

Question 9

What is papilloedema?

Answer 9

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.

Question 10

How does papilloedema cause the optic disc to bulge forward?

Answer 10

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.

Question 11

How does papilloedema appear on fundoscopy?

Answer 11

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

Question 12

What are gliomas?

Answer 12

Tumours of the glial cells in the brain or spinal cord. Glial cells surround and support the neurones.

Question 13

3 main types of glial cells?

Answer 13

Astrocytes

Ependymal cells

Oligodendrocytes

Question 14

Function of astrocytes?

Answer 14

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)

Question 15

Function of ependymal cells?

Answer 15

Controlling the production and flow of cerebrospinal fluid (CSF), brain metabolism, and waste clearance.

Question 16

Function of oligodendrocytes?

Answer 16

They create the myelin sheath around neuron axons, which allows for faster and more efficient communication between neurons.

Question 17

What is the difference between oligodendrocytes and schwann cells?

Answer 17

Both these cells have the same function however oligodendrocytes operate in the CNS whilst schwann cells operate in the PNS.

Question 18

What are the main 3 glioma types from most to least malignant?

Answer 18

Astrocytoma (the most common and aggressive form is glioblastoma)

Oligodendroglioma

Ependymoma

Question 19

What are meningiomas?

Answer 19

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.

Question 20

What cancers often spread to the brain?

Answer 20

The cancers that most often spread to the brain are:

Lung
Breast
Renal cell carcinoma
Melanoma

Question 21

Pituitary tumours are usually benign however can still result in clinical issues, how is this?

Answer 21

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.

Question 22

Pituitary tumours can grow large enough and can also cause hormone deficiencies or excessive release of hormones, what can this lead to?

Answer 22

Acromegaly (excessive growth hormone)

Hyperprolactinaemia (excessive prolactin)

Cushing’s disease (excessive ACTH and cortisol)

Thyrotoxicosis (excessive TSH and thyroid hormone)

Question 23

How can pituitary tumours be managed?

Answer 23

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

Question 24

What are acoustic neuromas?

Answer 24

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.

Question 25

What is another name for acoustic neuroma?

Answer 25

Vestibular schwannoma

Question 26

Usually acoustic neuromas are unilateral. What condition is associated with bilateral acoustic neuromas?

Answer 26

Neurofibromatosis type 2 (NF2)

Question 27

Typical presentation for acoustic neuromas?

Answer 27

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)

Question 28

What are management options for acoustic neuromas?

Answer 28

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

Question 29

What is the first line imaging examination for a suspected brain tumour?

Answer 29

MRI scan of the brain

Question 30

How can biopsy be used in treatment of brain tumour?

Answer 30

Biopsy gives the definitive histological diagnosis, usually obtained during surgery to remove the tumour.

Question 31

Management of brain tumour is dependant on type and grade, guided by MDT. What are the main options?

Answer 31

Surgery

Chemotherapy

Radiotherapy

Palliative care

Question 32

What type of brain tumour has a “fried egg” appearance when viewed under microscopy?

Answer 32

Oligodendrocytes

Question 33

What is the most common type of glioma?

Answer 33

Astrocytoma

Question 34

What are the 4 main astrocytoma classifications?

Answer 34

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.