CNSpathologyThirdyearmedicalstudents

DrHeyamAwad2018

Lecture13:CNStumours3/3

meningioma

•Arisefromarachnoidmeningothelialcells.•Ariseinadults•Attachedtothedura•Canbeseenatexternalsurfacesofthebrainorwithintheventricularsystem

meningioma

•Majority:canbeeasilyseparatedfrombrain,butsomeareinfiltrative•Behaviour:benignbutinfiltrativelesionsrecur•Outcomedependson:size,location,histologicalgrade

Histologicalgrades

•WHOI:(welldiff)meningioma•WHOII:atypicalmeningioma•WHOIII:anaplastic(malignant)meningioma

Grade1meningiomas

•Welldefined,durabasedmasses•Maycompressbutdonotinvadebrain•Canextendtooverlyingbone

• Grade1meningiomas/histologicaltypes• •Syncytial:whorledclusterswithoutvisiblecellmembranes.• •Fibroblastic:elongatedcellsandabundantcollagen• •Transitional:featuresofboth,syncytialandfibroblastic• •Psammomatous:numerouspsammomabodies

syncitial

fibroblastic

pasammomatous

AtypicalmeningiomaWHOgrade2

•Highcellularity•Prominentnuclei•Highmitoticrate•Moreaggressivethangrade1•Recur

Atypicalmeningioma

Anaplasticmeningioma

• AnaplasticmeningiomaWHOgrade3•Highlyaggressive•Resemblesarcomas

PrimaryCNSlymphoma

• Mostly:diffuselargeBcelllymphoma.•1%ofintracranialtumors.•PrimaryCNSlymphomaisthemostcommonCNSneoplasmintheimmunocompromised…inthissituationtheyarealmostalwayspositiveforEBV((Epstein– Barrvirus)

CNSlymphoma

• Aggressivediseasewithpoorprognosis•Poorresponsetochemotherapyascomparedtoperipherallymphomas•Usuallymultiplenoduleswithinthebrainparenchyma•Spreadingoutsidethebrainhappensrarelyandatlatestages•Peripherallymphomararelyspreadstothebrain,ifitdoesthereisusuallyassociatedmeningealandCNSinvolvement.

lymphoma

• Involvesdeepgreymatter,whitematter,cortex•Periventricularspreadiscommon•Tumornodulesmoredefinedthangliomasbutlessthanmetastases•EBVpositivetumorsusuallyhaveextensiveareasofnecrosis•Majority:diffuselargeBcelllymphomas

lymphoma:notethemultiplicityofthelesions

lymphoma

Metastatictumors

- ¼to½ofintracranialtumors•Mostcommonprimarysites:lung,breast,melanoma,kidneyandGIT.•Formdiscretewelldefinedmasses,canbemultiple

Paraneoplasticsyndromes

•CNSandperipheralnervescanbeaffectedindisseminatedcanceraspartoftheparaneoplasticsyndromes•Theseincludeseveralmanifestationsincludingdementia,ataxia,sensoryneuropathyandpsychosis

Familialtumorsyndromes

•Inheritedsyndromes•Mutationsinseveraltumorsuppressorgenes•Associatedwithincreasedriskofcertaintypesofcancer•2syndromeswithCNSinvolvement:TuberoussclerosisandvonHippel- Lindou

•Tuberoussclerosis

• Autosomaldominant• Hamartmasandbenignneoplasmsinbrainandothersites• CNStumors:corticaltubersandsubependymalhamartomas

• Tuberoussclerosis

•Corticaltubers:looklikepotatoes!!•Tuber:thickenedundergroundpartofastem

• Corticaltubers:Hamartomascomposedofhaphazardlyarrangedlargeneurones.• Mixtureofglialandneuronalcells• Causeseizures

Tuberoussclerosis..potatoesinthebrain!

• Subependymaltubers:Similartocorticaltubers• Cancausehydrocephalus

• Tuberoussclerosis/Extracerebrallesions

• renalangiomyolipoma,• retinalglialhamartomas,• pulmonarylymphangiomatosis• cardiacrhabdomyoma• cystsinliver,kidney,pancreas.• skinlesions:angiofibroma,hypopigmentedareas,thichenedpatches.

•VonHippelLindausyndrome

• Autosomaldominant• MutationinVHLtumorsupressorgene.• Hemangioblastomasmainlyincerebellarhemispheres,retina.• Cystsinpancreas,liverkidney• Increaseriskofrenalcellcarcinoma