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60 Cards in this Set
- Front
- Back
What are brain neoplasms?
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Space Occupying lesions within the skull and spinal canal
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Are brain tumor more prevelant in adults or children?
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Children (20%)
Adults only 2% |
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The age distribution of brain tumors has what shape?
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Bimodal
First peak in kids <5 Second, larger peak in adults 45-70 |
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What tumors occur more frequently in males?
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Gliomas and embryonal tumors
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What tumors occur more frequently in females?
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Meningiomas
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What is the etiology of most brain tumors?
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Sporadic and of unknown etiology
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What is the sole environmental factor clearly associated with increased risk of brain tumors?
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X-irradiation
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What are the 4 main signs/symptoms of brain tumors?
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1. Focal Epilepsy (seizures)
2. Mental Changes 3. Neurological deficit 4. Obstructive hydrocephalus |
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What are the 4 signs/symptoms of raised intercranial pressure?
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1. Headache (particularly due to POSITION at night or early morning)
2. Projectile Vomiting 3. Papilledema 4. Clouding of consciousness and coma |
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What can often occur as a result of increased ICP?
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herniation
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What are 4 herniations that can result from increased ICP?
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1. Subfalcine
2. Transtentorial (Uncal) 3. Tonsillar 4. Bilateral (central) transtentorial |
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What type of herniation can lead to cardio-respiratory arrest?
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Tonsillar Hernation
(due to compression of vascular supply) |
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Subfalcine hernation can result in infarction of what vessel?
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ACA
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Transtentorial (uncal) herniation can result in infarction of what vessel?
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PCA
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What are duret hemorrhages?
What causes them? |
Brainstem hemorrhages caused by transtentorial (uncal) herniation
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What are the 2 main consequences of herniation?
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1. Blood vessel compression
2. Nerve compression |
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What 3 cerebral structures (ie nerves) are most likely compressed by a herniation?
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1. Abducens (CN VI)
2. Occulomotor (CN III) 3. Cerebral Peduncle |
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The majority of pediatric neoplasms are what type of tumors?
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Tumors of neuroepithelial origin
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What cells give rise to most primary CNS neoplasms?
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Glial Cells
Give GLIOMAS |
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What are the 2 main categories of astrocytic tumors?
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1. Infiltrating Astrocytomas
2. Non-Infiltrating |
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What are the 3 types of Infiltrating Astrocytomas?
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1. Diffuse Astrocytoma (Grade II)
2. Anaplastic Astrocytoma (Grade III) 3. Glioblastoma (Grade IV) |
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What are the 3 types of non-infiltrating astrocytomas?
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1. Pilocytic astrocytoma
2. Pleomorphic xanthoastrocytoma (PXA) 3. Subependymal giant cells astrocytoma (SEGA) |
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What is seen on CT/whole brain in a diffuse astrocytoma?
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- Diffusely invading tumor
- Causes distortion/expansion of normal structures - Midline shift |
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What is seen histologically in a Diffuse Astrocytoma (II)?
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Pink meshwork of fibrillary processes
Condensed around irregularly scatter, hyperchromatic nuclei |
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What is NOT seen in a Diffuse Astrocytoma?
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1. Mitosis
2. Necrosis 3. Vascular Changes |
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What does a gemistocytic astrocytoma look like histologically?
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Largely plump cells with glassy pink cytoplasm
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What is seen histologically in Anaplastic Astrocytoma (III)?
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Foci or increased cell density and pleomorphism
Mitotic figures present |
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What does a glioblastoma tumor (IV) have that lesser grades do not?
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Necrotic and hemorrhagic masses
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What is seen histologically in a glioblastoma?
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- Very diverse appearance
- High cellularity - Multiple foci of necrosis |
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In addition to diverse cytologic features, what else characterizes a glioblastoma (IV)?
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Neovascularization (microvascular proliferation)
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What is the term for the areas of necrosis observed in Glioblastomas (IV)?
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Pseudopalisading necrosis
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What important astrocytomas occurs mainly in children and young adults?
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Pilocytic Astrocytoma (recall: non-infiltrative tumor type)
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Where in the brain in a pilocytic astrocytoma usually found in children?
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Cerebellum
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Does a pilocytic astrocytoma infiltrate surrounding tissues?
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No
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What is the prognosis of pilocytic astrocytomas?
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Good
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What do pilocytic astrocytomas usually look like histologically?
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Biphasic architecture with compact and cystic/spongy pattern
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What tumor type have smell centrally located nuclei with halo (fried egg) appearance around them
Also has branching vessels resembling "chicken wire" |
Oligodendroglioma
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What is the most common genetic alteration in oligodendrogliomas?
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Loss of heterozygozity for chromosomes 1p and 19q
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Does the loss of heterozygozity for chromosomes 1p and 19q in oligodendroglioma give a good or bad prognosis?
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GOOD
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What tumor type produces "pseudorosettes" of neoplastic cells clustered around blood vessels?
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Ependymoma
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What is the most important embryonal tumor?
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Medulloblastoma
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What is seen histolologically in a medulloblastoma?
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"Round Blue Cell Tumor"
Densely packed cells with round nuclei Mitoses are frequent |
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What histologic feature is seen in about 40% of medulloblastomas?
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Homer Wright (neuroblastic) rosettes
BUT are NOT centered around a vessel |
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How can neuroepithelial differentiation be detected in a medulloblastoma?
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Antibody to neurofilament proteins
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What is a tumor of the meninges called?
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Meningioma
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What is seen histologically in a menigioma?
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Whorls and Cords of neoplastic cells
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Menigiomas are typically what grade?
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I
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Menigiomas may arise from what?
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Neurofibramatoma type I/II
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What is the tumor most frequently associated with radiation exposure?
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Meningioma
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What is usually seen in terms of number of metastatic tumors?
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Multiple CNS tumors
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What are the 4 most common primary sites of metastatic brain tumors?
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1. Lung
2. Breast 3. Kidney 4. Colon |
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What is the main tumor of cranial and paraspinal nerves?
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Schwannoma
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What is the most common nerve associated with a schwannoma?
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Vestibulocochlear (CN VIII)
and also CN V |
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Are most schwannomas benign or malignant?
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Benign
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What 2 patterns are seen in schwannomas histologically?
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1. Antoni A pattern - compact areas with spindle shaped cells arranged in fasicles
2. Antoni B pattern - areas of loosely arranged meshwork of cells in a myxoid background |
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Apart from a schwannoma, what is the other tumor of cranial/paraspinal nerves?
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Neurofibroma
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What are the 2 types of neurofibroma?
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1. Dermal
2. Intraneural (peripheral nerves) |
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The presence of multiple neurofibromas is usually seen in the context of what?
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NF1
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What is seen histologically in a neurofibroma?
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HYPOCELLULAR with haphazardly arranged cells
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How is neurofibroma different from a schwannoma?
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Arises diffusely from endoneural fibroblastsa and eventually infiltrates entire nerve rather than just displacing it
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