Flashcards in Lecture 8 - Tumour Deck (22):
What are the two types of brain tumours?
- primary cns tumour - arise from abnormal proliferation of cells
- metastatic tumour - arise from neoplasms originating elsewhere in the body.
What are the types of secondary tumours?
What cells cause tumours?
astrocytes and oligodendrocytes become tumours.
What is the most common type of intracranial tumour
next is metastases
WHERE are tumours most common in adults?
they are mostly (70%) supratentorial (Above the tentorium cerebelli)
in children, it is the reverse.
What are symptoms of tumour?
intracranial pressure triad
- nausea and/or vomitting
- seizures - usually in oligodendrogliomas and meningiomas
really depends on the location, size and rate of growth.
What does it mean when a tumour is benign?
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
risk factors to brain tumour?
Exposure to vinyl chloride
Immune system disorders
Describe treatment for brain tumours.
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.
What is a glioma?
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+
What is the butterfly glioma
these are gliomas which cross the midline, via the corpus callosum
usually a gliobastoma multiforme
these are high grade astrocytomas.
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.
mutated oligodendrocyte cells, which usually make the myelin.
these tumours will spread through the CSF, but usually not outside the CNS.
What are ependymomas
mutated ependymal cells, which line the ventricles.
these can block the csf from exiting the ventricles, causing hydrocephalus.
What is a pituitary adenoma
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.
What are lymphomas
arise from b lymphcytes and commonly arise adjacent to lateral ventricles.
Where to schwannomas arise usually
Some extrinsic tumours?
Pineal region tumours
And colloid cysts
What are meningiomas
- 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.
What are the most common paediatric brain tumours?
- posterior fossa astrocytoma.
these are all basically in the posterior fossa, and causes hydrocephalus via obstruction of 4th ventricle or cerebral aqueduct.
What are the most common brain tumours in adults
which usualyl 50% of the time occurs from lung cancer.