Lecture 8 - Tumour

Question 1

What are the two types of brain tumours?

Answer 1

• primary cns tumour - arise from abnormal proliferation of cells
• metastatic tumour - arise from neoplasms originating elsewhere in the body.

Question 2

What are the types of secondary tumours?

Answer 2

metastatic

local invasion

Question 3

What cells cause tumours?

Answer 3

not neurons.

astrocytes and oligodendrocytes become tumours.

Question 4

What is the most common type of intracranial tumour

Answer 4

glioma

next is metastases

Question 5

WHERE are tumours most common in adults?

Answer 5

they are mostly (70%) supratentorial (Above the tentorium cerebelli)

in children, it is the reverse.

Question 6

What are symptoms of tumour?

Answer 6

intracranial pressure triad

• headache
• nausea and/or vomitting
• papilledema
• seizures - usually in oligodendrogliomas and meningiomas

really depends on the location, size and rate of growth.

Question 7

What does it mean when a tumour is benign?

Answer 7

Brain tumours are benign if they do not infiltrate or disseminate widely through the nervous system and malignant if they have the potential to spread.

tumours rarely exit the CNS

Question 8

risk factors to brain tumour?

Answer 8

Radiation exposure
Exposure to vinyl chloride
Immune system disorders

Question 9

Describe treatment for brain tumours.

Answer 9

Most of the time, surgical removal of as much of the tumour as possible, without causing serious deficits, is undertaken.
90% positive effect.

Next, depending on where it is, chemotherapy, radiation therapy and steroids may be used.

Question 10

What is a glioma?

Answer 10

A general category of cancer that includes astrocytomas, oligodendrogliomas, and ependymomas

Usually classified using the Daumas-Dupont grading system, wehre IV is the most malignant (glioblastoma multiforme)

Occurs in 90% of brain tumours in those aged 45+

Question 11

What is the butterfly glioma

Answer 11

these are gliomas which cross the midline, via the corpus callosum

usually a gliobastoma multiforme

these are high grade astrocytomas.

Question 12

Describe astrocytomas

Answer 12

Astrocytomas come from astrocytes, which are glial cells that help nourish neurons.

these tumours are classified by how class the cells are together in the tumour, how abnormal they are, how many are proliferating, whether blood vessels are growing near the tumour, and weather some of the cancer cells have degenerated or not.

Question 13

Describe oligodendrogliomas

Answer 13

mutated oligodendrocyte cells, which usually make the myelin.

these tumours will spread through the CSF, but usually not outside the CNS.

Question 14

What are ependymomas

Answer 14

mutated ependymal cells, which line the ventricles.

these can block the csf from exiting the ventricles, causing hydrocephalus.

Question 15

What is a pituitary adenoma

Answer 15

It causes endocrine disturbances or compresses the optic chiasm, usually resulting in bitemporal visual field loss - tunnel vision.

dopaminergic agonists can shrink these. if doesnt work, then resection.

prolactin secreting - will cause galactorrhea, intertility, amenorrhea, loss of public hair, impotence,

growth hormone secreting - coarse features, englarged jaw, nose, cardiac/pulmonary disease, spinal deformation, diabetes.

acth secreting - adrenal cortical hyperplasia - cushing syndrome - buffalo hump, hypertension, pendulous abdomen, striate.

Question 16

What are lymphomas

Answer 16

arise from b lymphcytes and commonly arise adjacent to lateral ventricles.

Question 17

Where to schwannomas arise usually

Answer 17

CN VIII

cochlear-vestibular nerve.

Question 18

Some extrinsic tumours?

Answer 18

(benign)

 Meningioma.
 Acoustic neuroma.
 Pituitary adenoma
 Craniopharyngioma, 
 Chordoma
 Pineal region tumours 
 And colloid cysts

Question 19

What are meningiomas

Answer 19

• arise from arachnoid villus cell.
• occur in the lateral convexities, the falx cerebelli, and along the basal regions of the cranium.
• associated with breast cancer in females.
• treated by excision
• only 5% behave in a malignant way.
• can push onto brain
• attached to dura
• hyperostosis or invasion of skull occurs.

Question 20

What are the most common paediatric brain tumours?

Answer 20

• posterior fossa astrocytoma.
• medulloblastomaa
• ependymoma

these are all basically in the posterior fossa, and causes hydrocephalus via obstruction of 4th ventricle or cerebral aqueduct.

Question 21

What are the most common brain tumours in adults

Answer 21

metastatic

which usualyl 50% of the time occurs from lung cancer.

Question 22

What are hereditary tumour syndromes?

Answer 22

NF1 - cafe au lait spots, dermatofibromas, optic nerve gliomas, plexiform neurofibroma, malignant peripheral nerve sheath tumours.

NF2 - bilateral acoustic neuroma, multiple meningiomas, epndymomas.