INTRACRANIALNEOPLASMSOregonHealthScienceUniversity颅内肿瘤俄勒冈健康与科学大学

1、primary intracranial neoplasmsmonika arora, ms 4lyudmila morozova, ms 4imaging for brain tumors1skull x-rays: rarely necessary. useful in demonstrating calcification, erosion, or hyperostosisct: most widely used for diagnosis of brain tumors will detect 90% of tumors, but might miss: small tumors (m

2、facts: arise from arachnoidal cap cell type from the arachnoid membraneusually non-invasive associated with nf-2location:parasagittal region sphenoid wingparasellar regionpresentation:asymptomatic symptomatic: focal or generalized seizure or gradually worsening neurologic deficit meningioma1on imagi

3、ng ct: isodense or hypodense, homogenous extra-axial mass with smooth or lobulated, clearly demarcated contours which enhance homogenously and densely with contrast frequently have areas of calcification and produce hyperostosis of adjacent bone. mri isointense with gray matter on t1 images enhance

4、with contrast often with enhancing dural trail extending from the tumor attachmentgliomas arise from glial cells astrocytomasastocytomas fall on a gradient that ranges from benign to malignant oligodendrogliomaslow grade pilocytic astocytomasglioblastoma multiformebenignmalignantdiffuse low grade as

5、trocytomasastrocytoma1,2,3: diffuse low grade astrocytomaepi: 15% of astrocytomasyoung adultsfacts: widely infiltrate surrounding tissuelocation:frontal regionsubcortical white matterpresentation:seizuresheadacheslowly progressive neurologic deficitson imaging: ct: well circumscribed, non enhancing,

6、 hypodense or isodense lesion mri: mri more sensitive than ct useful for identification and establishing extentt1 image shows abnormal areas of decreased signalt2 image shows abnormal areas of increased signalusually no enhancement cystt1 weightedt2 weightedastrocytoma1,2,3: high grade astrocytoma:

7、glioblastomaepi: most common type of primary brain tumor in adultsage of presentation: 40-60, mffacts: may arise de novo or evolve from a low-grade glioma tumor infiltrates along white matter tract and can cross corpus callosumpoor prognosiscan look like a butterfly lesionlocation: frontal & tem

8、poral lobes basal gangliapresentation:seizures, headacheslowly progressive neurologic deficitsastrocytoma1: high grade astrocytoma: glioblastomaon imaging: variablect: hypodense or isodense central hypodense area of necrosis surrounded by thick enhancing rimsurrounding edemamri: t1 image shows low s

9、ignal intensityt2 image shows high signal intensityoligodendroglioma1,2,3epi: 5-10% of primary brain tumors mean age of onset 40 yearsfacts: distinguished pathologically from astrocytomas by the characteristic “fried egg” appearance. arises from myelinlocation: superficially in frontal lobespresenta

10、tion: seizures most common headache slowly progressive neurologic deficitsoligodendroglioma1on imaging: ct: well circumscribed, hypodense lesions with heavy calcificationcystic degeneration is common but hemorrhage & edema are uncommonmri:hypointense or isointense on t1-weighted imageshyperinten

11、se on t2-weighted images with variable enhancementgerminoma1,2,3facts: germ cell tumorscauses parinauds syndrome disorder characterized by fixed upward gazelocation:commonly in pineal region (50%)overlies tectum of midbrainpresentation:obstructive hydrocephalus due to aqueductal stenosison imaging:c

12、t isodense or hyperdense enhances with contrastmriisointense or hypointense on t1-weighted images & enhance with gadoliniumhyperintense on t2 imagest1 imagescolloid cyst of the ventricle4epi: usually in adults 1% of all intracranial tumorsfacts: managed surgically causes hydrocephalus by obstruc

13、tive flow endodermal originlocation: foramen of monro anterior aspect of third ventriclepresentation: headaches vertigo memory deficitscolloid cyst of the ventricle on imaging: ct: smooth, round lesions lesion hyperdense to brain tissue thin rim of enhancement after iv contrast mri: t1-weighted hype

14、rintense lesion due to proteinaceous nature. t2-weighted shows hypointense lesioninfratentorial tumors1 choroid plexus papillomas cerebellar astrocytomas medulloblastomas hemangioblastomas ependymomas brainstem gliomas schwannomas pituitary adenomas craniopharyngiomaschoroid plexus papillomas1,2,3ep

15、irepresents 2% of gliomasone of the most common brain tumors in patients malemedian age at diagnosis is 50account for 80-90% of cerebellopontine angle tumorscomprise 8% of intracranial tumors in adults; rare in children (except with nf-2)factsunilateral in 90% of cases (r=l);bilateral acoustic neuro

16、mas are diagnostic of nf-2; presentationpatients may present with asymmetric sensorineural hearing loss, tinnitusfluctuating unsteadiness while walking, vertigo (although only 1% of patients with vertigo had schwannomas);if cn v nerve is affected, facial numbness, pain, and hyperesthesia may be pres

17、ent;if cn vii is affected, facial paresis may be present.tumor progression may lead to compression of brainstem or cerebellum leading to ataxia, tonsil herniation, and hydrocephaluslocationarise from vestibular division of cn viii; majority benignschwannomas1,2,3 imaging mri: with gadolinium is more

18、 sensitive in detection of schwannomas (when compared to ct); it can detect tumors as small as 1-2 mm; seen as enhancing lesion in the region of cpa; fine-cut ct through internal auditory canal can detect large or medium tumors.pituitary adenomas1,2,3 epi most common tumors of pituitary gland repres

19、ent 8% of primary brain tumors facts out of pituitary adenomas, prolactinomas are the most common; presentation may cause hypopituitarism and visual field defects; patients should have endocrine, radiographic, and ophthalmologic assessments.pituitary adenomas1,2,3imaging: plain x-ray may show an enl

20、arged sella turcica; ct scan will detect only large adenomas; it will show a large hyper- or isodense lesion; mri is the imaging of choice; microadenomas (lesions 1 cm) will be seen as a low intensity lesions on t1; gadolinium will enhance the normal gland that is adjacent to adenoma macroadenomas w

21、ill appear as isointense on t1 and will enhance uniformly with gadoliniumcraniopharyngiomas1,2,3epi represent 1-3% of primary brain tumors bimodal distribution: first peak infants and children; second peak 55-65 year oldfacts derived from epithelial remnants of rathkes pouch; slow growing; benign te

22、nd to recur even after “complete” removal 20-year survival rate of children with craniopharyngiomas is about 60%.location located in suprasellar fossa and inferior to optic chiasmpresentation cause bitemporal hemianopsia and hypopituitarism; frequently present with headache; craniopharyngiomas1,2,3

23、imaging cystic calcified parasellar lesion could be seen on radiograph;brainstem gliomas1,2,3epimale=femaleaccount for 10-20% on all cns tumorsmore common in children (account for 20% of all intracranial neoplasms under the age 15);in children, median age at diagnosis is 5-9 years of age.factsnf-1 i

24、s the only known risk factormostly benign (but range from benign to very aggressive);long term survival for low-grade gliomas is near 100%.locationin peds, 80% arise in pons, with 20% arise in medula, midbrain, and cervicomedulary junction;presentationmost patients with low-grade brainstem gliomas h

25、ave a long history of minor signs and symptoms; may present with neck pain or torticollis;medulary tumors may present with cranial nerve palsies, dysphagia, nasal speech and apnea, n/v, ataxia,or weakness;may cause “locked-in” syndromebrainstem gliomas1,2,3imagingmri is the method of choice to image

26、 those tumors (brainstem glioma appears isodense on cr and can be missed);appear isointense or hypointense on t1 images, hyperintense on t2, and inhance uniformly and brightly with iv contrast;now test yourself by playing:name that tumorname that tumor may present with endocrine abnormalities presen

27、ts with bilateral temporal hemianopsia answer: pituitary adenomaname that tumor age 40-60 very malignant “butterfly lesion” answer: glioblastomaname that tumor unilateral in 90% of cases bilateral lesions seen almost exclusively in nf2 answer: schwannomaname that tumor bimodal distribution derived f

28、rom rathkes pouch answer: craniopharyngiomaname that tumor 2nd most common brain tumor arises from arachnoid cap cells answer: meningiomaname that tumor slow growing arises from myelin answer: oligodendogliomaname that tumor most likely a pnet tumor highly radiosensitive 2nd most common tumor in children answer: medulloblastomaname that tumor overlies tectum & midbrain can cause obstructive hydrocephalus due