Brain metastases (N)

Question 1

What are brain metastases the most common cause of?

Answer 1

Metastatic brain cancer is the most common form of brain tumours in adults

Question 2

Which cancers most commonly metastasise to the brain? (6)

Answer 2

• lung (most common)
• breast
• colorectal
• testicular
• skin (melanoma)
• kidney

Question 3

What are the clinical features of brain metastases? (5)

Answer 3

• persistent headaches - worse in mornings and when lying down (suggests raised ICP)
• seizures
• focal neurological deficits (e.g. changes in speech, vision, hearing)
• cognitive deficits
• CN VI palsy (medially diverted eye) and diplopia may be first presentation

Question 4

What is the first-line investigation for brain metastases?

Answer 4

Imaging (CT/MRI) - can see well-circumscribed tumours at junction of grey and white matter

Question 5

What imaging do you do for progressively worsening headache with higher cognitive function impaired?

Answer 5

Brain MRI over CT as you can see more detail of brain anatomy

Question 6

What is the first-line management for brain metastases?

Answer 6

High-dose dexamethasone (reduces cerebral oedema)

Question 7

How do we manage limited brain metastases?

Answer 7

Surgical resection

Question 8

What management options do we have for extensive brain metastases? (3)

Answer 8

• stereotactic radiosurgery
• whole brain radiation therapy
• chemotherapy

Question 9

Describe the prognosis of brain metastases.

Answer 9

Mean survival approximately 1 month without treatment and <1 year with treatment

Question 10

Describe glioblastoma multiforme. (5)

Answer 10

• glioblastoma is the most common primary tumour in adults associated with poor prognosis (~1y)
• Ix - imaging: solid tumours with central necrosis and a rim that enhances with contrast
• disruption of BBB - associated with vasogenic oedema
• histology: pleomorphic tumour cells border necrotic areas
• Rx: surgical with postoperative chemo and/or radiotherapy; dexamethasone for cerebral oedema

Question 11

Describe meningioma. (7)

Answer 11

• second most common primary brain tumour in adults (after glioblastoma)
• typically benign, extrinsic tumours of CNS
• arise from arachnoid cap cells of the meninges and are typically located next to the dura and cause Sx by compression rather than invasion
• typically located at falx cerebri, superior sagittal sinus, convexity or skull base
• histology: spindle cells in concentric whorls and calcified psammoma bodies
• Ix: CT (will show contrast enhancement) and MRI
• Rx: observation, radiotherapy or surgical resection

Question 12

Describe vestibular schwannoma. (6)

Answer 12

• benign tumour arising from CN VIII (vestibulocochlear nerve)
• Sx: hearing loss, facial nerve palsy (compression) and tinnitus
• neurofibromatosis type 2 associated with bilateral vestibular schwannomas
• histology: Antoni A or B patterns seen
• Verocay bodies (acellular areas surrounded by nuclear palisades)
• Rx: observation, radiotherapy or surgery

Question 13

Describe pilocytic astrocytoma.

Answer 13

• most common primary brain tumour in children
• histology: Rosenthal fibres (corkscrew eosinophilic bundle)

Question 14

Describe medulloblastoma. (4)

Answer 14

• aggressive paediatric brain tumour that arises within the infratentorial compartment
• spreads through CSF system
• histology: small, blue cells; rosette pattern of cells with many mitotic features
• Rx: surgical resection and chemotherapy

Question 15

Describe ependymoma. (3)

Answer 15

• commonly seen in 4th ventricle
• may cause hydrocephalus
• histology: perivascular pseudo-rosettes

Question 16

Describe oligodendroma. (2)

Answer 16

• benign, slow-growing tumour common in frontal lobes
• histology: calcifications with ‘fried-egg’ appearance

Question 17

Describe hemangioblastoma. (3)

Answer 17

• vascular tumour of cerebellum
• associated with von Hippel-Lindau syndrome
• histology: foam cells and high vascularity

Question 18

Describe pituitary adenoma. (7)

Answer 18

• benign tumours of pituitary gland
• secretory (produce hormone in excess) or non-secretory
• divided into microadenomas (<1cm) or macroadenomas (>1cm)
• Sx: consequences of hormone excess (e.g. Cushing’s due to ACTH, or acromegaly due to GH) or depletion
• compression of optic chiasm –> bitemporal hemianopia due to crossing nasal fibres
• Ix: pituitary blood profile + MRI
• Rx: hormonal or surgical (e.g. transphenoidal resection)

Question 19

Describe craniopharyngioma. (7)

Answer 19

• most common paediatric supratentorial tumour
• solid/cystic tumour of the sellar region that is derived from remnants of Rathke’s pouch
• common in children, but can also present in adults
• Sx: may present with hormonal disturbance, Sx of hydrocephalus or bitemporal hemianopia
• histology: derived from remnants of Rathke’s pouch
• Ix: pituitary blood profile + MRI
• Rx: usually surgical +/- postoperative radiotherapy