1
Q
What is the epidemiology of intracranial tumours?
A
10-17 per 100,000
2
Q
What is the epidemiology of intraspinal tumours?
A
1-2 per 100,000
3
Q
about __ - __% are primary tumors – the rest are metastases from other organs
A
50 – 75
4
Q
brain tumours Account for __% of all childhood cancers
A
20
5
Q
__% of childhood CNS tumors arise in the posterior fossa
A
70
6
Q
__% of CNS tumours tend to arise above the tentorium cerebelli in adults
A
70
7
Q
What can a slow-growing, well-differentiated tumour in the brain cause?
A
- Compression or destruction of smaller, critical brain areas such as the medulla
- Tumours that are difficult to isolate from normal brain tissue can result in extensive destruction when they are removed
- Damage to the blood-brain barrier or development of epilepsy due to the tumour or its removal
8
Q
T/F: Aggressive, poorly differentiated brain tumours are among the deadliest of cancers
A
True
9
Q
What are the most common types of gliomas?
A
astrocytomas
10
Q
What are tumours of the higher-grade (IV) going to exhibit?
A
- greater anaplasia
- greater invasion into the surrounding tissue
- Increased necrosis and more sites of hemorrhage/BBB incompetence
11
Q
__ = abnormal cellular morphology, greater rate of mitosis
A
Anaplasia
12
Q
What grade is pilocytic astrocytoma (commonly-used name)?
A
Grade I
13
Q
What grade is diffuse astrocytoma?
A
Grade II
14
Q
What grade is anaplastic astrocytoma?
A
Grade III
15
Q
What grade is glioblastoma multiforme (commonly-used name)?
A
Grade IV
16
Q
Who do grade I astrocytomas tend to occur in?
A
children & young adults
17
Q
Where are grade 1 astrocytomas often found in?
A
cerebellum, optic nerves, 3rd ventricle
18
Q
What are characteristics of a grade I astrocytoma?
A
- Can be a solid or a cystic mass – either way, the tumour is well-differentiated and relatively easy to separate from surrounding normal brain tissue
- cells = large and have only have 2 processes
- few hemorrhage areas, less necrosis, preservation of BBB
19
Q
What are the underlying processes that lead to grade I astrocytoma?
A
Usually excessive activation of Raf (gene called BRAF) –> Growth factors are responsible for activating
–> constantly having growth factor on
20
Q
Who are grade II and III astrocytomas more likely to be found in?
A
adults
21
Q
Where are grade II and III astrocytomas located?
A
tentorium of cerebellum
22
Q
What are characteristics of Grade II astrocytoma?
A
poorly differentiated cells, invade surrounding brain
23
Q
What are characteristics of grade III astrocytoma?
A
similar to grade II, but more mitotic figures, larger cells, more mitotic figures
24
Q
What are mutations that cause grade II & III astrocytomas?
A
- PTEN: inactivated PTEN excessive signaling through the PI3K pathway
- Increased EGF or PDGF receptor activity or expression - Epidermal growth factor, platelet-derived growth factor
- P16, p14 or p53 inactivation
- IDH mutations – isocitrate dehydrogenase mutations that produce a metabolite (2-hydroxyglutarate) that “dysregulates” epigenetic signaling in the glial cell excessive activation of the RAS pathways
25
What is the most common brain tumour in adults with the worst prognosis?
Grade IV atsrocytomas
26
What are characteristics of grade IV astrocytomas?
- Prominent hemorrhage, necrosis, rapid growth
- Tends to invade the adjacent tissue more than other types
27
What are common mutations that cause grade IV astrocytomas?
p53, EGFR (epidermal growth factor receptor) mutations are more common
28
What are signs and symptoms of astrocytomas?
- Headache (worse in morning), intensified by straining and coughing
- Nausea, vomiting
- 6th cranial nerve palsy
- Focal changes caused by invasion/damage of normal brain tissue - Seizures, hemiparesis, ataxia, memory loss… many
29
__% of astrocytomas are Grade II – IV
80
30
What is the survival rate of Grade II astrocytoma?
5-6 years
31
What is the survival rate of Grade IV?
<1 year
32
What is the survival rate of grade III astrocytoma?
10-20% 5-year survival rate
33
What are characteristics of astrocytomas that obtain the worst prognosis?
- Infiltration of normal tissue
- Hemorrhage and necrosis
- Rapid cell division
34
What is the best diagnosis method for astrocytomas?
MRI
35
What is the best treatments for astrocytomas?
Treatment depends on the type of tumour - Radiation, chemotherapy, surgery all commonly used
36
What are signs and symptoms of increased cranial pressure?
- Slowing of mental capacity
- headaches (especially if more severe in the morning)
- vomiting (more likely in the morning)
- blurred and/or double vision - blurred = optic nerve atrophy due to papilledema, double vision = 6th cranial nerve palsy (usually)
- In kids – precocious puberty, stunted growth due to hypothalamic impairment
- Difficulty walking (spasticity)
37
Brain tumours are common causes of?
brain herniations
38
What are common brain herniations that are more likely to occur with cerebral masses?
sub-falcine & transtentorial
39
What is the percentage that oligodendrogliomas represent of gliomas?
5-15%
40
What age are oligodendrogliomas more common in?
40's and 50's
41
Where are oligodendrogliomas common found?
cerebral hemispheres around white matter
42
What is the most common mutation of oligodendrogliomas?
IDH mutations
43
What is different about the oligodendrocytes in oligodendrogliomas?
they are surrounded by a capsule
44
What are the signs and symptoms of oligodendrogliomas?
- Signs and symptoms typical of slowly increase in intracranial pressure
- seizures are quite common
45
How do you diagnose oligodendrogliomas?
MRI
46
T/F In general, oligodendrogliomas prognosis is usually worse than that of astrocytomas, determined on a case-by-case basis
False, better
47
What do ependymomas arise from?
ependymal cells of the ventricular system
48
What do ependymomas block in kids? What does this cause?
- block the central canal or are near the 4th ventricle in kids
- They also can produce lots of CSF
- Therefore can cause communicating (excess CSF) or non-communicating
49
Where are ependymomas found in adults?
spinal cord
50
When are ependymomas easier to remove?
Easier to remove when found in the spinal cord, difficult to remove from other locations
51
Which ependymomas have a worse prognosis?
Ependymomas in the 4th ventricle/posterior fossa have a worse prognosis
52
What are signs and symptoms of ependymomas?
- Signs and symptoms are typical of hydrocephalus and elevated intracranial pressure if in the cranium
- If spinal cord compression - paresis, pain, sensory deficits
53
What are usually fairly benign tumours of adults?
meningiomas
54
What are meningiomas attached to? Where do they arise?
attached to the dura, often arise from the meningothelial cell of the arachnoid
55
meningiomas compose about __% of all primary brain tumours
20
56
Where are meningiomas usually found?
- along the external surfaces of the brain
- within the ventricular system
57
What are the pathological findings of meningiomas?
- Rounded masses with a dural base that compress underlying brain but are easily separated from it by a thin fibrous capsule
- Sometimes extension into the overlying bone or “sheet-like” spreading through the brain can occur
58
What are clinical features of meningiomas?
- Symptoms/signs of elevated intracranial pressure
- Symptoms/signs caused by compression of the cortex near the falx cerebri, wing of the sphenoid, foramen magnum
- Interestingly, meningiomas tend to grow quite rapidly during pregnancy (not sure why)
59
What is the prognosis of meningiomas?
Prognosis tends to be good – they tend to grow slowly and do not usually invade adjacent tissue
60
What is the main treatment of meningiomas?
surgery
61
A tumour with very poorly-differentiated, “primitive-looking” cells
medulloblastoma
62
What are characteristics of medulloblastoma?
- Rapid growth, highly anaplastic
- Can metastasize widely, and can even extend down into the cauda equina
63
Who can medulloblastomas occur in?
children & adults
64
Where do medulloblastomas grow? What does this cause?
Only grows in the cerebellum, and can obstruct CSF flow (due to encroachment on the 4th ventricle)
65
What are signs and symptoms of medulloblastomas due to?
due to damage to the cerebellum and impaired drainage of CSF (hydrocephalus)
66
What is the prognosis of medulloblastoma?
Has a good prognosis because it is very responsive to radiation therapy
67
Where are brain metastases often found? Where can they penetrate to?
Brain metastases are often found on/in the meninges but can also penetrate deep into cortical structures
68
What are the 5 most common primary (initial) sites that cancers end up metastasizing to brain later?
- Lung
- Breast
- Melanoma (skin)
- Kidney
- GI tract cancers
69
What are clinical features of brain metastases?
- Elevated intracranial pressure findings
- Focal findings from invasion and damage of specific brain structures
70
T/F: Most cancers have a relatively poor prognosis after brain metastases have occurred
True
BMS100 Neuropathology
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