brain tumours

Question 1

Glioblastoma multiforme

Answer 1

• Glioblastoma is the most common primary tumour in adults and is associated with a poor prognosis (~ 1yr).
• On imaging they are solid tumours with central necrosis and a rim that enhances with contrast. Disruption of the blood-brain barrier and therefore are associated with vasogenic oedema.
• Histology: Pleomorphic tumour cells border necrotic areas
• Treatment is surgical with postoperative chemotherapy and/or radiotherapy. Dexamethasone is used to treat the oedema.

Question 2

Meningioma

Answer 2

The second most common primary brain tumour in adults

• Meningiomas are typically benign, extrinsic tumours of the central nervous system. They arise from the arachnoid cap cells of the meninges and are typically located next to the dura and cause symptoms by compression rather than invasion.
• They typically are located at the falx cerebri, superior sagittal sinus, convexity or skull base.
• Histology: Spindle cells in concentric whorls and calcified psammoma bodies
• Investigation is with CT (will show contrast enhancement) and MRI, and treatment will involve either observation, radiotherapy or surgical resection.

Question 3

Vestibular schwannoma

Answer 3

• A vestibular schwannoma (previously termed acoustic neuroma) is a benign tumour arising from the eighth cranial nerve (vestibulocochlear nerve). Often seen in the cerebellopontine angle. It presents with hearing loss, facial nerve palsy (due to compression of the nearby facial nerve) and tinnitus.
• Neurofibromatosis type 2 is associated with bilateral vestibular schwannomas.
• Histology: Antoni A or B patterns are seen. Verocay bodies (acellular areas surrounded by nuclear palisades)
• Treatment may involve observation, radiotherapy or surgery.

Question 4

Pilocytic astrocytoma

Answer 4

The most common primary brain tumour in children
* Histology: Rosenthal fibres (corkscrew eosinophilic bundle)

Question 5

Medulloblastoma

Answer 5

• A medulloblastoma is an aggressive paediatric brain tumour that arises within the infratentorial compartment. It spreads through the CSF system. Treatment is surgical resection and chemotherapy.
• Histology: Small, blue cells. Rosette pattern of cells with many mitotic figures

Question 6

Ependymoma

Answer 6

• Commonly seen in the 4th ventricle
• May cause hydrocephalus
• Histology: perivascular pseudorosettes

Question 7

Oligodendroma

Answer 7

• Benign, slow-growing tumour common in the frontal lobes
• Histology: Calcifications with ‘fried-egg’ appearance

Question 8

Haemangioblastoma

Answer 8

• Vascular tumour of the cerebellum
• Associated with von Hippel-Lindau syndrome
• Histology: foam cells and high vascularity

Question 9

Pituitary adenoma

Answer 9

• Pituitary adenomas are benign tumours of the pituitary gland. They are either secretory (producing a hormone in excess) or non-secretory. They may be divided into microadenomas (smaller than 1cm) or macroadenoma (larger than 1cm).
• Patients will present with the consequences of hormone excess (e.g. Cushing’s due to ACTH, or acromegaly due to GH) or depletion. Compression of the optic chiasm will cause a bitemporal hemianopia due to the crossing nasal fibers.
• Investigation requires a pituitary blood profile and MRI. Treatment can either be hormonal or surgical (e.g. transphenoidal resection).

Question 10

Craniopharyngioma

Answer 10

• Most common paediatric supratentorial tumour
• A craniopharyngioma is a solid/cystic tumour of the sellar region that is derived from the remnants of Rathke’s pouch. It is common in children, but can present in adults also. It may present with hormonal disturbance, symptoms of hydrocephalus or bitemporal hemianopia.
• Histology: Derived from remnants of Rathke pouch
• Investigation requires pituitary blood profile and MRI. Treatment is typically surgical with or without postoperative radiotherapy.