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27 Cards in this Set
- Front
- Back
How much is known about the pathogenesis of CNS tumors?
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Very little
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What are 4 factors that may contribute to nervous system tumor formation?
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-Genetic disposition
-Hamartomatous/vestigial tissues -Viral infections -Carcinogenic chemicals |
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What are 3 hereditary familial diseases associated with nervous system tumors?
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-von Recklinghausen's
-von Hipple-Lindau's disease -Tuberous sclerosis |
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What 3 tumors are associated with von Recklinghausen's neurofibromatosis?
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-Neurofibroma
-Glioma -Meningioma |
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What tumor is associated with von Hipple-Lindau's disease?
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Hemangioblastoma
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What tumor is associated with Tuberous sclerosis?
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Subependymal giant cell astrocytoma
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What are 2 other tumors that are often familial?
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-Retinoblastoma
-Medulloblastoma |
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What chromosomal abnormalities are associated with neuroblastomas?
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-Ch 1
-Ch 17 |
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Whatever the actual cause, what is presently considered to be responsible for initiating tumor formation in the nervous system?
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Activation of oncogenes
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What are 2 broad categories of effects of brain tumors?
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-Local effects
-General effects (complications) |
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What are the local effects of brain tumors caused by?
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Destruction of brain tissue by the tumor
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What are general effects of tumors caused by?
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The fact that these are space-occupying lesions.
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How do general effects of tumors compare to local effects?
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They are more serious, self-perpetuating, and will lead to death if unrelieved.
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What are 4 general effects or complications of cns tumors?
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-Brain edema
-Hydrocephalus -Internal herniation w/ secondary vascular effects -Pressure effects on the skull and spinal cord |
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Why do tumors in the brain cause edema?
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Because of vascular injury and resulting increased capillary permeability
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So what is the more prominent form of edema seen caused by brain tumors?
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Vasogenic > cytotoxic
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Where is the main site of edema due to tumors?
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White matter
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What are 2 mechanisms of hydrocephalus caused by tumors?
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-Obstruction of foramen of monro
or aqueduct by the tumor -Decreased CSF absorption due to generalized tumor infiltration of the meninges |
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What are 4 types of internal herniations that can occur due to nervous system tumors?
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-Cingulate (subfalcine)
-Uncal -Hippocampal -Tonsillar |
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What can cause such internal herniation?
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-The tumor itself
-Pressure from hydrocephalus or brain edema |
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When will external herniation of the brain outside the skull only be seen?
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If the dura and skull have been partially removed by surgery
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What effects can increased ICP have on the sella turcica?
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-Flattening of the dorsum
-Flattening of posterior clinoid processes |
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What is the most common and serious consequence of an intraspinal, extramedullary neoplasm?
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Spinal cord compression
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What does tumor compression of the blood vessels by an extramedullary intraspinal neoplasm result in?
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Compression necrosis and ischemic infarction.
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What is a more important determinant of clinical severity of a brain tumor (even benign) than for other organ tumors?
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Location
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What can make a benign tumor clinically malignant?
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Being located in a vital area like the brainstem.
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Do primary brain tumors metastesize very often?
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no
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