GranulomatousDiseases

PRACTICALFoundation BlockPathology 2019

1- Tuberculosisofthelung

Foundation BlockPathology Dept, KSU

Thegranulomashaveareasofcaseousnecrosis.Thispatternofmultiplecaseatinggranulomas

PulmonaryTB– CaseousNecrosis– Gross

Foundation BlockPathology Dept, KSU

Primarytuberculosisisthepatternseenwithinitialinfectionwithtuberculosisinchildren.Reactivation,orsecondarytuberculosis,ismoretypicallyseeninadults.

PulmonaryTB- Ghon’sComplex– Gross

Foundation BlockPathology Dept, KSU

Initial(primary)infectionwithT.B.producingasub-pleurallesioncalledaGhon’s focus.TheearlyGhon’s focustogetherwiththelymphnodelesionconstitutetheGhon’s complex..

CAVITARY TUBERCULOSIS: Extensive necrosis with cavitation, usually occurring in the upper lung or apex, is a characteristic feature of "secondary" or "adult tuberculosis”

Secondary tuberculosis

• MiliaryTBcanoccurwhenTBlunglesionserodepulmonaryveinsorwhenextrapulmonary TBlesionserodesystemicveins.

• Thisresultsinhematogenousdisseminationoftuberclebacilliproducingmyriadsof1-2mm.lesionsthroughoutthebodyinsusceptiblehosts.

• Miliary spreadlimitedtothelungscanoccurfollowingerosionofpulmonaryarteriesbyTBlunglesions.

MiliaryTBoftheLungs

Foundation BlockPathology Dept, KSU

Well-definedgranulomasareseenhere.Theyhaveroundedoutlines.TheonetowardthecenterofthephotographcontainsseveralLanghan’sgiantcells.

Granulomasarecomposedoftransformedmacrophagescalledepithelioidcellsalongwithlymphocytes,occasionalPMN's,plasmacells,andfibroblasts

TuberculousGranulomas

Foundation BlockPathology Dept, KSU

Thepyknoticnucleiofepithelioidcellsinthecenterofthegranuloma(apoptoticbodies)areaprecursorofnecrosis.

PulmonaryTB- Granulomawithcentralearlynecrosis

Foundation BlockPathology Dept, KSU

Theedgeofagranulomaisshownhereathighmagnification.Attheupperisamorphouspinkcaseousmaterial[1]composedofthenecroticelementsofthe

granulomaaswellastheinfectiousorganisms.Thisareaisringedbytheinflammatorycomponent[2]withepithelioidcells,lymphocytes,andfibroblasts.

1

2

TuberculousGranulomas

Foundation BlockPathology Dept, KSU

AstainforAcidFastBacilliisdone(AFB stain)tofindthemycobacteria.Themycobacteriastainasredrods,asseenhereat

highmagnification.

AcidFastbacilliofMycobacteriumTBintheLung

Foundation BlockPathology Dept, KSU

2- TuberculousLymphadenitis

Foundation BlockPathology Dept, KSU

Foundation BlockPathology Dept, KSU

TuberculousLymphadenitis- Gross

TuberculousLymphadenitis– CutSection

Sectionofalymphnodewithconnectivetissuecapsuleandlymphoidtissue

Foundation BlockPathology Dept, KSU

Manyroundandovaltubercles/granulomaswithorwithoutcentralcaseationthatappearsstructureless,homogenousandpinkincolour.

TuberculousLymphadenitis

Foundation BlockPathology Dept, KSU

Thegranulomasconsistsofepithelioidcells,fewlanghan’sgiantcells(largecellwithmultiple

peripheralnuclei)andperipheralrimoflymphocytes

TuberculousLymphadenitis

Foundation BlockPathology Dept, KSU

3- BilharzialGranulomas

Foundation BlockPathology Dept, KSU

ColonicBilharziasis- HPF

Colonbiopsyofbilharziasis.Fibrosingforeignbodygranulomaagainstthemiracidium-containingovumofS.mansoniisobservedinthesubmucosallayer

(H&E). Foundation BlockPathology Dept, KSU

Schistosomahaematobium.UrinaryBladderbiopsyshowingbilharziasis eggs– granulomawitheosinophils

BilharziasisoftheUrinaryBladder

Foundation BlockPathology Dept, KSU

S.japonicumeggsinhepaticportaltract

S.japonicumintheHepaticportaltract

Foundation BlockPathology Dept, KSU

4- CutaneousLeishmaniasis

Foundation BlockPathology Dept, KSU

CutaneousLeishmaniasis

Leishmaniasisiscausedbyparasiticinfection,mainlybyparasitesoftheLeishmaniagenuswhicharecarriedbyablood-suckinginsectknownasthe

sandfly.Foundation BlockPathology Dept, KSU

Histologicalviewshowsmarkedcellularinfiltrationandparasites(Leishmanbodies)withinmacrophages

CutaneousLeishmaniasis

Foundation BlockPathology Dept, KSU

CutaneousLeishmaniasis

ThebloodfilmshowsmacrophagescontainingLeishmaniaamastigotes,eachwithaprominentkinetoplast(seenasadarkenedspotnexttothelargernucleus)and

noflagella(incontrastwiththepromastigoteform).

Foundation BlockPathology Dept, KSU

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