Brain Tumors

Glial Cells.Neurons

Glial Cells What Is a Brain Tumor?Primary vs. secondary: May lodge into the ff structures:- Brain parenchyma most common area of metastases- Leptomeninges pia mater & arachnoid- Dural spaceLocalized vs. invasiveTHEY CAN ALSO BE:WHO GRADING SYSTEMWHO Histologic Classification of Tumors of the CNSTumors of Neuroepithelial TissueTumors of Cranial and Spinal NervesTumors of the MeningesTumors of Uncertain HistogenesisHemangioblastoma from primitive vascular structuresLymphomas and Hematopoietic NeoplasmGerm Cell TumorEx: Germinoma common in pineal gland areaCysts and Tumor-like lesionsUsually in the third ventricleTumors of the Sellar RegionsLocal Extension from Regional TumorsMetastatic TumorsWhat Causes a Brain Tumor?

Occupational exposuresCommon Types of Brain Tumors

Astrocytomas come in four major subtypes:juvenile pilocytic astrocytoma (grade 1)fibrillary astrocytoma (grade 2)anaplastic astrocytoma (grade 3)glioblastoma multiforme (grade 4)The higher the grade, the more aggressive the tumor.

Age IncidenceAdults- Supratentorial: 80-85%- Intratentorial: 15-20%- Children- Intratentorial: 60%- Supratentorial: 40%

Clinical PresentationSlowly Progressive TumorsCerebral DysfunctionCerebellar Dysfunction

Increased ICP

Papilledema

Course of Illness

Ancillary ProceduresTreatment of Brain TumorsThe Neurological Rehabilitation team:

The Rehabilitation Team24The Rehabilitation TeamCommon types of brain tumors

I. GLIOMAS- Most common primary brain tumor- 50% of all symptomatic brain tumors- Incidence increases with advancing age- Peak in 8th and 9th decades- No known environmental factors- No behavioral lifestyle choices- Ionizing radiation: the only clear risk factor- Originate from glial cells or their stem cell precursorsGLIOMASInclude:a. Astrocytomab. Oligodendrogliomac. Ependymoma- WHO Classification Basisa. Increased cellularityb. Nuclear atypiac. Endothelial proliferationd. Necrosis

A. Astrocytoma- Most common glioma- Cerebral astrocytoma (more in adults)- Behavioral changes- Seizures- Hemiparesis- Language difficulty- Cerebellar astrocytoma (more in children)- Hemisphere- Ataxia- Brain stem (children)- Pons- CN deficitsGrade I: Pilocytic AstrocytomasPrimary in children & young adultsFocal astrocytoma may be associated with:Neurofibromatosis type I (NF-I)Unusually excellent prognosis

Grade II: Diffuse or Fibrillary AstrocytomaMost common in the cerebral hemisphere in young adultsLow grade or benign histologicallyInfiltrative usually a problem because the tumor cannot be resected completely if this is a characteristic of the tumorComplete resection not possibleLatent potential for malignant transformation

Grade III: Anaplastic AstrocytomaGrade IV: Glioblastoma multiformeGrades III and IV are high-grade gliomas20% of all intracranial tumors55% of gliomas80% of gliomas of the cerebral hemispheres in adultsPeak incidence middle to late adulthoodMales/females = 1.61No familial predilectionAnaplastic AstrocytomaHave increased pleomorphism, enlarged nuclei and most importantly, increased proliferative activity that is reflected as increased mitotic activity.There should be NO necrosis or endothelial proliferation.Presence of either/both is suggestive of worse biological behavior.

Glioblastoma MultiformeCSF seeding:Malignant cells in the CSF may form:a. Distant foci in spinal rootsb. White spread meningeal gliomatosisCSF seeding implies that GBM can go to the CSF spaces such as the subarachnoid space & communicate with the ventricular systemExtraneural metastasis- To bone & lymph nodes (very rare) after a craniotomyPseudopalisading around the necrosis is common in GBMCan cross the midline in a butterfly pattern: this shows the aggressive nature of this tumor because the midline is composed of a tough dura

Glioblastoma Multiforme

Imaging: High- and Low-Grade GliomasHigh-grade or malignant gliomas: appear as contrast enhancing mass lesions which arise in white matter & are surrounded by edemaLow-grade gliomas: typically non-enhancing lesions that diffusely infiltrate brain tissue & may involve a large region of brainLow-grade gliomas are usually best appreciated on T2- weighted MRI scans.Prognosis of AstrocytomasMedian survivalGBM: 1 yearAnaplastic astrocytoma: 3 yearsLow-grade astrocytoma: 5 yearsOthers survive a decade or moreMost die from transformation of tumor to higher gradeB. OligodendrogliomaDerived from oligodendrocytes or their precursorsOligodendrocytes produce the white matter in the brain5-7% of all intracranial gliomasMost often in the 3rd and 4th decadesMales:females = 2:1Found primarily in cerebral hemispheres, within the brain parenchymaHighly infiltrativeMay metastasize distantly in ventricular & subarachnoid spaces like the GBM (CSF seeding)Round regular fried-egg cellsOligodendroglioma

fried egg cells of oligodendroglioma

Prognosis of OligodendrogliomaMedian SurvivalLow-grade oligodendrogliomas: 8-16 yearsAnaplastic oligodendrogliomas: 5 yearsTumors that have 1p/19q LOHbest prognosisMany pxs die from malignant transformation of the tumorC. EpendymomaArise from ependymal cells (an intraventricular tumor)More common in children10% pediatric intracranial tumors5% of adult intracranial tumorsMost common in the 4th ventricleAtaxia, vertigo, increased ICPMay grow in brain parenchyma without obvious attachment to the ventricular systemSpinal lesions more common in adultsIntracranial ependymomas predominate in childrenEpendymoma

Histological Characteristics of Ependymoma

Prognosis5-year survival: 40-50%10-year survival: 47-68%Better prognosis:Young ageInfratentorialGross total excisionLow-grade histologyII. MENINGIOMASecond most common primary brain tumorOriginate from arachnoid cells (meningoepithelial cap cells normally seen in arachnoid villi)20% of all intracranial tumors (with asymptomatic cases40% or more)7% of all posterior fossa tumors3-12% of cerebellopontine angle tumorsMENINGIOMA

II. MENINGIOMAMost diagnosed in 6th % 7th decadesFemale: Male3:2 to 2:1Multiple in 5-15% (NF-2)90% intracranial10% intraspinalSpinal meningioma: 10x in womenAll familial meningiomas occur with NF-2Rare in children (more in boys)- Rare with dural attachments- Usually Intraventricular or posterior fossa- Commonly with sarcomatous changes- Frequently with NF-2

Etiology of MeningiomaProgesterone receptors- Expressed in 80% of women with meningiomas- Expressed in 40% of men with meningiomas

PathologyNodular tumors occasionally meningiomas en plaque (sheer-like formation)Highly vascularEncapsulated and attached in the dura (blood supply from external carotid artery)Hyperostosis of adjacent bone (bone proliferation)Histological CharacteristicsBenignTypical features:- Whorls of arachnoid cells surrounding a central hyaline material that eventually calcifies to form PSAMMOMA BODIES- No characteristic cytologic markerClinical ManifestationsSome are asymptomaticfound incidentally by MRIBut may have symptoms:Tumor location: by compression of underlying neural structuresSites of predilection- Cerebral convexity (Sylvian & parasagittal areas)- Falx cerebri- Skull base- Olfactory groove- Sphenoid ridge- CP angle- Tuberculum selladiagnosisdiagnosisCranial CT ScanIsointense or slightly hyperintenseHyperostosis20%Isointense (65%) or hypointense (35%) in T1 and T2Gadolinium AngiographyHypervascular massembolization reduce the risk of intraoperative bleedingMR Angiography & VenographyGrowth Rate of MeningiomaLess than 1 cm per year (very slow growth but can recur)Tumor doubling time: 1.27 to 14.35 yearsSurgeryComplete excision may cure many meningiomasThe extent of resection is the most important in determining recurrenceFor recurrence: reresectionRadiation TherapyResidual tumor after surgeryRecurrent tumorAtypical or malignant histologyIII. TUMORS OF THE PITUITARY GLANDThird most common primary brain tumorOften asymptomaticIncidence at autopsy: 1.7 24%Most common in adults in the 3rd and 4th decade10% incidence in children & adolescentsNot hereditary except MEN-1 (multiple endocrine neoplasia)

PathologyMicroadenoma- Less than 1cm- Symptoms due to excess hormone secretion (or hyperfunctioning)a. Growth hormoneb. Gonadotropinc. Thyroid hormoned. Adrenal hormonee. Prolactin hormoneMacroadenoma- More than 1cm- Symptoms due to compressing normal pituitary gland and neural structure causing hypofunctioning

PathologyEndocrine Active (Secretory)- Prolactinoma- Most common secretory intrasellar endocrine active tumor- Secreted either by microadenoma or macroadenoma- Growth hormone- Before closure of epiphysis gigantism- After closure of epiphysis acromegaly- ACTH: Cushings Syndrome- FSH and LH- Endocrine Inactive (Non-secretory or null cell adenoma)- 10% mixed secretory tumorHistological characteristics:Almost all are histologically benignPituitary CA: rareMacroadenomasPituitary Carcinoma

MacroadenomasMay invade dural boneMay infiltrate surrounding structureLocally invasive pituitary adenomas are nearly always histologically benignPleomorphism and mitotic figure insufficient for diagnosis of carcinoma (may be seen in benign adenomas)Invasive character independent of growth ratePituitary CarcinomaHighly invasiveRapidly growing & anaplasticUnequivocal diagnosis relies on presence of distant metastasis

Clinical Manifestations of Tumors of the Pituitary GlandCompression of neural and vascular structuresHeadacheHypopituitarismVisual symptoms- visual loss- visual field abnormality: bitemporal hemianopsia is the most commonPapilledema is rareMay enlarge with pregnancy5% of pituitary adenoma present with pituitary apoplexyClinical Manifestations of Tumors of the Pituitary GlandOptic chiasm- Between hypothalamus & sella turcica- When this is compressed bitemporal hemianopsiaOptic nerve- When this is compressed ipsilateral blindnessOptic tract- When this is compressed contralateral homonymous hemianopsiaDiaphragma sella- The dura that covers sella turcicaAs tumor grows forward to the sella compress the basal dura headache affected pain-sensitive intracranial structures- Basal dura is a pain-sensitive intracranial structureVISUAL FIELD PATHWAYS

bitemporal hemianopsia

IPSILATERAL BLINDNESS

contralateral homonymous hemianopsia

Hypothalamus + thalamus- Form the lateral wall of the 3rd ventricle- Any pathology in the ventricular system will cause accumulation of CSF proximal to the block hydrocephalusSuprasellar region region of the hypothalamusAn example of a suprasellar tumor is a craniopharyngoma in children & adultsA craniopharyngoma can compress the third ventricle & cause the ff: (hydrocephalus with signs of increased ICP)- Headache- Vomiting- PapilledemaNowadays, pituitary adenoma usually does not grow until the region of the hypothalamus because visual problems prompt consult & diagnosis.Papilledema is also rare because it manifests late in the course of the tumor. Before that happens, patient must have been diagnosed alreadyObstructive hydrocephalus: rare because of diagnosis at visual problem levelPituitary Apoplexy- Hemorrhage or infarction of pituitary adenoma- Sudden onset of headache, nausea, vomiting, visual loss, diplopia, altered mental status- Diagnosis by CT or MRI- Treatment emergency surgeryDiagnosis- X-ray will show you ballooning of the sella turcica- Cranial MRI- Best way to evaluate pituitary pathologyTreatment

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