Inflammation

PRACTICAL

I- AcuteInflammation

Foundation BlockPathology 2019

PathogenesisofExudation

Thediagramshownhereillustratestheprocessofexudation,aidedbyendothelialcellcontractionandvasodilation,whichtypicallyismostpronouncedinvenules.Collectionoffluidinaspaceisatransudate.Ifthisfluidisprotein-richorhas

manycellsthenitbecomesanexudate.

Foundation BlockPathology Dept, KSU

ExudationintheAlveolarSpace

HereisvasodilationwithexudationthathasledtoanoutpouringoffluidwithfibrinintothealveolarspacesalongwithPMN'sindicativeofanacute

bronchopneumoniaofthelung,Foundation BlockPathology Dept, KSU

ExudationofFibrininAcuteInflammation

HereisanexampleofthefibrinmeshinfluidwithPMN'sthathasformedintheareaofacuteinflammation.Itisthisfluidcollectionthatproducesthe

"tumor"orswellingaspectofacuteinflammation.Foundation BlockPathology Dept, KSU

InflammationwithNecrosis- LPF

Thevasculitisshownheredemonstratesthedestructionthatcanaccompanytheacuteinflammatoryprocessandtheinterplaywiththecoagulationmechanism.Thearterialwallisundergoingnecrosis,

andthereisthrombusformationinthelumen. Thisisseeninconnectivetissuedisorderduetoautoimmunediseasee.g.rheumatoidarthritis

Foundation BlockPathology Dept, KSU

VasculitisArterialwallwithsevereinflammationandfibrinoid necrosis

InflammationwithNecrosis- HPF

Athighermagnification,vasculitiswitharterialwallnecrosisisseen.Notethefragmentedremainsofneutrophilicnuclei(karyorrhexis).Acuteinflammationisa

non-selectiveprocessthatcanleadtotissuedestruction

Foundation BlockPathology Dept, KSU

Fibrinoid necrosis

1- FibrinousPericarditis

Foundation BlockPathology Dept, KSU

Here,thepericardialcavityhasbeenopenedtorevealafibrinouspericarditiswithstrandsofstringypalefibrinbetween

visceralandparietalpericardium

AcuteFibrinousPericarditis- Gross

Foundation BlockPathology Dept, KSU

AcuteFibrinousPericarditis- Gross

Serousfluidatthebottomofthepericardialcavity(arrow)isvisible.Theepicardialsurfaceappearsroughened,comparedtoitsnormalglistening

appearance;duetothestrandsofpink-tanfibrinthathaveformed

Foundation BlockPathology Dept, KSU

Thefibrinousexudateisseentoconsistofpinkstrandsoffibringuttingfromthepericardialsurfaceattheupperright . Theexudateonthesurfaceisshownenlargedintheinset. Noteaconsiderablenumberoferythrocytes

trappedinthemeshoffibrinthreads.

AcuteFibrinousPericarditis-Microscopically

Foundation BlockPathology Dept, KSU

Right

Left

Thepericardiumisdistortedbythickirregularlayerofpinkishfibrinousexudatewithsomeredcellsandinflammatorycells

AcuteFibrinousPericarditis- LPF

Foundation BlockPathology Dept, KSU

Thesubpericardiallayeristhickenedbyedemaandshowsdilatedbloodvessels,chronicinflammatorycellsandareasof

calcification.

AcuteFibrinousPericarditis- HPF

Foundation BlockPathology Dept, KSU

AcuteFibrinousPericarditis- HPF

Meshwork of fibrin

Inflammatorycells(neutrophils andmonocytes)

2- AcuteAppendicitis

Foundation BlockPathology Dept, KSU

NormalAppendix- Gross

Thisisthenormalappearanceoftheappendixagainstthebackgroundofthecaecum.

Foundation BlockPathology Dept, KSU

AcuteAppendicitis- Gross

Seenhereisacuteappendicitiswithyellowtotanexudateandhyperemia,includingtheperiappendicealfatsuperiorly,ratherthana

smooth,glisteningpaletanserosalsurfaceFoundation BlockPathology Dept, KSU

AcuteAppendicitis– Longitudinalsection

Acaseofacuteappendicitis:Theorganisenlargedandsausage-like(botuliform).Thislongitudinalsectionshowstheangryredinflamedmucosawithitsirregularluminalsurface.Thisappendixdoesnotshowlatecomplications,liketransmuralnecrosis,perforation,and

abscessformation

Foundation BlockPathology Dept, KSU

AcuteAppendicitis– LPFofthecutsection

Foundation BlockPathology Dept, KSU

SmoothMusclelayer

AcuteAppendicitis– LPF

FibrosisofLaminapropriaScattered

Neutrophilsintheepithelium

LymphFollicle

LuminalDebris

Foundation BlockPathology Dept, KSU

AcuteAppendicitis– HPF

ScatteredNeutrophilsinthecryptepithelium

Foundation BlockPathology Dept, KSU

Thisslideshowsthemusclelayeroftheappendixwhichispermeatedwithnumerouspolymorphonuclearleukocytes

AcuteAppendicitis– Histopathology

Foundation BlockPathology Dept, KSU

3- AcuteCholecystitis

Foundation BlockPathology Dept, KSU

AcuteCholecystitis– Gross

Mucocele,stoneobstructedtheneck,distended,aspirationdoneandremovedbylapchole

Foundation BlockPathology Dept, KSU

Theneutrophilsareseeninfiltratingthemucosaandsubmucosaofthegallbladderinthispatientwithacutecholecystitisandrightupper

quadrantabdominalpainwithtendernessonpalpation

AcuteCholecystitis– HistopathologyHPF

Foundation BlockPathology Dept, KSU

4- SkinPilonidalSinus

Foundation BlockPathology Dept, KSU

ForeignBodyReaction(PilonidalSinus)

Apilonidalsinusisasinustractwhichcommonlycontainshairs.Itoccursundertheskinbetweenthebuttocks(thenatalcleft)ashortdistanceabovetheanus.Usuallyrunsverticalbetweenthebuttocksandrarelyoccurring

outsidethecoccygealregion.

Foundation BlockPathology Dept, KSU

ForeignBodyReaction(PilonidalSinus)

Surgicallyexcisedpilonidalsinustracts

Foundation BlockPathology Dept, KSU

Thelumenofthesinusandwallcontainlargenumberofhairshaftswithforeignbodygiantcells,lymphocytes,macrophages&

neutrophils

PilonidalSinus– HistopathologyLPF

Foundation BlockPathology Dept, KSU

ChronicInflammation

Foundation BlockPathology Dept, KSU

1- Chroniccholecystitiswithstones

Foundation BlockPathology Dept, KSU

Grossappearanceofgallbladderaftersectioninglongitudinally.Noticethicknessofgallbladderwall,abundantpolyhedricstones

andsmallpapillarytumorinthecysticduct.

ChroniccholecystitiswithGallStones

Foundation BlockPathology Dept, KSU

Chroniccholecystitis- Histopathology

Irregularmucosalfoldsandfociofulcerationinmucosa.Wallispenetratedbymucosalglandswhicharepresentinmusclecoat(Rokitansky- Aschoffsinuses).Alllayersshowchronicinflammatorycellsinfiltrationand

fibrosis. Foundation BlockPathology Dept, KSU

Themucosaisatrophic,withasinglelayerofflattenedepithelium.Thereisproteinaceousfluidadherenttothemucosalsurface,withsomebilestainedorange-browncrystalstowardtheupperleftinthelumen.Thelaminapropria

showsfibrosisandcontainsamononuclearcellinfiltrate(smalldarkbluenuclei).

Themuscleishypertrophiedcomparedtonormalgallbladder.

Chroniccholecystitis- Histopathology

Foundation BlockPathology Dept, KSU

2- Brainabscess

Foundation BlockPathology Dept, KSU

CTofacerebralabscess.Thereisaliquefactivecenterwithyellowpussurroundedbyathinwall.Abscessesusuallyresultfromhematogenousspreadofbacterialinfection,butmayalsooccurfromdirectpenetrating

traumaorextensionfromadjacentinfectioninsinuses

BrainAbscess- CT

Foundation BlockPathology Dept, KSU

BrainAbscess- MRI

Thistrichromestaindemonstratesthelightblueconnectivetissueinthewallofanorganizingcerebralabscess.Normalbrainisattheleftandthe

centeroftheabscessattheright.Foundation BlockPathology Dept, KSU

Right

Left

3- Granulationtissue

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GranulationTissue- LPF

Sectionoffragmentsofedematous,looseconnectivetissueshowsmanysmallnewlyformedcapillarieslinedbyplumpendothelial

cells.ProliferationoffibroblastsisseenFoundation BlockPathology Dept, KSU

Inflammatorycellsincludingmacrophages,lymphocytes,plasmacellsandneutrophilsintheoedematousstroma.

Pinkhomogenouscollagenfibersmaybeidentified.

GranulationTissue- HPF

Foundation BlockPathology Dept, KSU