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ionizing radiation
associated with increased risk of meningiomas, astrocytomas, and sarcomas
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NF 1
chromosome 17
glioma (optic nerve) and ependymoma
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NF 2
chromosome 22q12 meningioma and glioma
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von hippel lindau
chromosome 3p25
hemangioblastoma
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li fraumeni cancer
chromosome 17p13.1
glioma and medulloblastoma
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signs of posterior fossa tumor in kids
decreased appetite and weight loss, reduced school performance, dizziness, ataxia, neck pain, bulbar weakness, gaze palsy, opisthotonos
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MRI spectroscopy sign of brain tumors
decreased peak of N-acetyl aspartate (NAA) associated with neuronal loss
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most common primary brain tumors
gliomas and meningiomas
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types of gliomas
- astrocytoma
- oligodendroglioma
- ependymoma
- choroid plexus papilloma
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GBM
arises from astrocytes. See necrosis and neovascular proliferation
tx: chemo - temozolamide and BCNU (gliadel wafers) implanted in cavity to slow delivery of the nitrosourea drug
prognosis: poor
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low-grade astrocytoma
arises from astrocytes or ependymoma cells
in kids, more common in cerebellar hemispheres, but more common in 4th decate of life
seizure typical presentation of slow growing tumors
prognosis: medial survival 7 years
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oligodendroglioma
arises from oligodendrocytes
peak incidence ages 35-45. common in frontal lobes, though can appear in basal ganglia and thalamus
calcifications common. microscopically "fried-egg" appearance (perinuclear halos with swollen cytoplasm)
prognosis: tends to recur locally and progress into a malignant form
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ependymoma
arises from ependymal lining of ventricles
in kids, 90% are intracranial (often 4th ventricle) with subarachnoid spread. in adults 75% arise in spinal canal as intramedullary tumors of spine
path: perivasular pseudorosettes
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meningioma
arises from meningothelial (mesodermal) cells of dura mater
almost always benign, more common in women ages 40-60. NF2 may cause.
path: sheets of plump, uniform meningothelial cells with tendency to form whorls. progesterone receptors found frequently. calcifications seen on CT
hyperostosis on CT may indicate tumor invasion of the bone
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medulloblastoma
arises at the medullary velum of the 4th ventricle. a primitive neuroectodermal tumors (PNET)
path: small round cells with high mitotic index
presents as fast growing tumor that infiltrates surrounding tissue and extends towards 4th ventricle, producing hydrocephalus with headache, unsteadiness, and vomiting. May spread via CSF
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schwannoma
arises from schwann cells
more common in middle-aged women, common in vestibular cranial nerve (acoustic neuroma) at the cerebellopontine agnle. Bilateral schwannomas in NF2
path: sheets of uniform spinde cells, forming palisades called verocay bodies
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ganglioglioma
seen in kids and young adults, include a mixture of neurons and glial cells. usually located in the cerebral hemisphere and have slow growth. T2 MRI shows characteristic swollen gyri. can be surgically removed
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hemangioblastoma
cerebellar cystic lesions, often associated with von hippel lindau disease (hereditary retinal angiomas, pancreatic cysts, and kidney tumors)
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Most frequent metastatic brain tumors
lung, skin (melanoma), kidney (renal cell carcinoma), breast, colon
located at junction of gray and white matter, tend to be solitary
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drop metastases
intradural extramedullary spinal mets that arise from intracranial lesions. most common source is ependymomas and medulloblastomas
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NF 2 associated tumors
bilateral vestibular schwannomas, meningiomas, and intramedullary ependymomas
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mets that bleed easily
melanoma, renal carcinoma, and choriocarcinoma
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