Chapter 28 part 6 Flashcards
1
Q
Hypoglycemia
A
- some regions of the brain are more sensitive to it
- pyramidal neurons of cerebral cortex
- hippocampus
- purkinje cells of the cerebellum
2
Q
hyperglycemia
A
-dehydration, confusion, stupor, coma
3
Q
hepatic encephalopathy
A
- impaired liver function
- elevated ammonia levels and proinflammatory cytokines
- astrocytes with enlarged nucleus–alzheimer type II cells
4
Q
carbon monoxide characteristic?
A
- injury of neurons–layers III and V of cerebral cortex, hippocampus, purkinje cells
- CO interacts with heme of cytochrome c oxidase–inhibit electron transport in mitochondria
5
Q
methanol-effects
A
- retina–degeneration of retinal ganglion cells–can cause blindness
- bilateral necrosis of putamen and focal white-matter necrosis–when severe exposure
- illicit liquor (moonshine) contaminated
6
Q
ethanol effects
A
- chronic–wernicke-korsakoff syndrome (from thiamine deficiency)
- cerebellar dysfunction–truncal ataxia, unsteady gait, nystagmus
- atrophy and loss of granule cells in anterior vermis
7
Q
radiation effects
A
-coagulative necrosis–edema in surrounding tissue, vascular fibrinoid necrosis, sclerosis
8
Q
70% of childhood tumors arise in?
A
- posterior fossa
- tumors of CNS account for 20% of all cancers in childhood
9
Q
most common group of primary brain tumors
A
-gliomas
10
Q
gliomas include
A
- astrocytoma
- oligodendroglioma
- ependymoma
11
Q
2 major categories of astrocytic tumors
A
- diffusely infiltrating astrocytomas
- more localized astrocytomas (pilocytic astrocytoma–most common)
12
Q
infiltrating astrocytomas–symptoms? range from?
A
- 80% of adult primary brain tumors
- 4-6 decades
- seizures, headaches, focal neurologic deficits
- diffuse astrocytoma (grade II/IV)
- anaplastic astrocytoma (grade III)
- glioblastoma (grade IV)
13
Q
glioblastoma occurs in 2 settings
A
- primary glioblastoma–older patients–new onset of disease
- secondary glioblastoma–progression of a lower-grade astrocytoma-younger patients
14
Q
glioblastoma–4 molecular subtypes
A
- classic subtype
- proneural
- neural
- mesenchymal
15
Q
glioblastoma classic subtype–genes
A
most primary glioblastoma
- mutation of PTEN tumor suppressor gene
- deletions of chromosome 10
- amplification of EGFR oncogene
16
Q
glioblastoma proneural type–genes
A
most secondary glioblastoma
- mutation of TP53, IDH1 and 2
- overexpression of receptor for PDGFRA
17
Q
glioblastoma neural type genes
A
- deletions of NF1
- TNF pathway and NFkB pathway–highly expressed genes
18
Q
most common theme of the subtypes of glioblastomas
A
-most affect 2 cancer hallmarks–sustained proliferative signaling, evasion of growth suppressors
19
Q
diffuse astrocytoma morphology
A
- poorly defined
- cellular density
- transition bw neoplastic and normal tissue is indistinct
20
Q
anaplastic astrocytoma–morphology
A
- more density cellular
- gemistocytic astrocytoma–brightly eosinophilic cell body, stout processes
21
Q
glioblastoma morphology
A
- variation in appearance of tumor from region to region
- some areas are firm/white; others soft/yellow (necrosis); others cystic degeneration and hemorrhage
- necrosis and vascular/endothelial cell proliferation
- pseudo-palisading–tumor cells on the edges of necrotic regions
22
Q
gliomatosis cerebri
A
- diffuse glioma, infiltration of multiple regions of brain
- aggressive–grade III/IV
23
Q
-well differentiated diffuse astrocytoma–outlook
A
- stable/progress slowly
- survival more than 5 years
- clinical deterioration occurs due to emergence of more rapidly growing tumor of higher histologic grade
24
Q
high grade astrocytoma outlook
A
- abnormal vessels are leaky, permeable BBB
- glioblastoma–prognosis is poor
25
pilocytic astrocytoma--characteristics and morphology
(grade 1)
- children, young adults
- occurs in patients with NF1 (functional loss of neurofibromin
- 2 alterations in BRAF signaling pathway also
- grow very slowly
- often cystic
- necrosis is uncommon
- limited infiltration of surrounding brain
26
brainstem glioma--when? anatomic patterns?
clinical subgroup of astrocytomas
- 1st 2 decades of life
- pontine gliomas (most common)--aggressive, short survival
- cervicomedullary jxn tumors--less aggressive
- dorsally exophytic gliomas--even more benign
27
oligodendroglioma--when? genes?
- infiltrating gliomas, resemble oligodendrocytes
- 4-5 decades
- neurologic complaints, seizures
- mutations of IDH1 and IDH2 (better prognosis)
- survival 5-10 years
28
oligodendroglioma--morphology
- well circumscribed, cysts, focal hemorrhage, calcification
- anastomosing capillaries
- grade II
29
anaplastic oligodendrogliomas
higher cell density, necrosis, mitotic activity
30
ependymoma--where? when? gene?
- ofern arise next to ependyma--lined ventricular system, central canal of spinal cord
- first two decades--near 4th ventricle
- in adults--spinal cord--NF2
31
ependymoma--morphology
- in 4th ventricle--well demarcated, but near vital pontine and medullary nuclei
- intraspinal tumors--sharp demarcation
- cells--regular, round to oval nuclei, chromatin
- perivascular pseudorosettes--tumor cells arranged around vessels, thin ependymal processes directed toward wall of vessel
32
ependymoma clinical features
- posterior fossa ependymomas--hydrocephalus (obstruction of 4th venricle)--worst outcome (5yr survival=50%)
- CSF dissemination is common
33
subependymomas-what are they?
- solid, sometimes calcified, slow-growing nodules attached to ventricular lining and protrude into ventricle
- usually asymptomatic
- can cause hydrocephalus
- mostly found in lateral and 4th ventricles
34
choroid plexus papillomas
- most common in children--lateral ventricles
- adults--4th ventricle
- exactly looks like structure of normal choroid plexus
- present with hydrocephalus
35
colloid cyst of 3rd ventricle
- non-neoplastic enlarging cyst
- young adults
- attached to roof of 3rd ventricle, can obstruct foramina of monro--cuases noncommunicating hydrocephalus--rapidly fatal
- headache
- cyst--thin, fibrous capsule, cuboidal epithelium
36
neuronal tumors--when?
far less common than glial tumors
| -seen in young adults--presents with seizures
37
gangliogliomas--what are they?
- mix of mature neuronal and glial cells
- superficial lesions--seizures
- most common neuronal tumors of CNS
- slow growing, but glial component can become anaplastic (then progresses rapidly)
- mutation in BRAF gene
- most often--temporal lobe-cystic component
38
dysembryoplastic neuroepithelial tumor--what are they?
- rare, low grade (I) tumor of childhood--seizures
- good prognosis after resection
- most often in superficial temporal lobe
39
central neurocytoma--what is it?
- low grade II in ventricular system
| - evenly spaced, round, uniform nuclei and often islands of neuropil
40
medulloblastoma
- malignant embryonal tumor, grade IV
- exclusively in cerebellum
- most common- 20% of brain tumors in kids
41
medulloblastoma--4 groups of genetics
- Wnt type (older children--prognosis is best!)
- SHH type (infants, young adults)
- group 3 medulloblastoma (MYC amplification, isochromosome 17-infants/children--worst prognosis)
- group 4 (isochromosome 17; without MYC amplification; some MYCN amplification--intermediate prognosis
42
medulloblastoma--morphology where?
- kids--midline of cerebellum
- adults-lateral
- hydrocephalus
- well circumscribed, densely cellular
43
nodular desmoplastic variant
-areas of stromal response--collagen, "pale islands" that have more neuropil and neuronal markers
44
large cell variant
-large irregular vesicular nuclei, mitosis, apoptotic cells
45
drop metastases
-form linear chains of cells that infiltrate through cerebellar cortex--spread to subarachnoid space
-dissemination through CSF--common complication!
gives rise to nodular masses some distance from primary tumor
46
atypical teratoid/rhabdoid tumor--when? where?
- highly malignant tumor--young children--grade IV
- posterior fossa, supratentorial compartments
- divergent differentiation with epith, mesenchymal, neuronal, glial components, often includes rhaboid cells
47
apical teratoid/rhabdoid tumor--genes, hallmark??
- alterations in chromosome 22--hallmark
| - hSNF5/INI1
48
apical teratoid/rhabdoid tumor--morphology/ clinical?
- large, soft
- rhabdoid cells
- highly aggressive--very young--before 5-live 1 year
49
primary CNS lymphoma
- most common CNS neoplasm in immunocompromised patients (infected by EBV)
- multifocal in brain parenchyma
- most are B-cell origin
- aggressive, bad outcomes
50
characteristic of primary brain lymphoma
-hooping--infiltrating cells separated from 1 another by silver staining material
51
intravascular lymphoma
- large cell lymphoma
- grows within small vessels
- instead of presenting as a mass lesion, the occlusion of vessels by malignant cells and results in infarcts
