blood cells morphology

8/6/2019 Blood Cells Morphology

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The morphology of Blood cells



Composition of the blood

The circulating blood is composed of plasmaand cells.The cells are red cells (or erythrocytes),

white cells (or leucocytes) and platelets .Blood cells can be identified in blood films

stained with a mixture of basic and acidicdyes.Normal white cells are divided intopolymorphonuclear leucocytes (orgranulocytes) and mononuclear cells.



White blood cells

There are three types of granulocyte named

according to theirstaining characteristics inblood films. They areneutrophils ,eosinophilsand basophils .

Mononuclear cells aredivided intolymphocytes andmonocytes .



Neutrophils

The neutrophils inthe circulatingblood are mainlymature segmented

neutrophils.



Band form NeutrophilsThere are smallernumbers of cells of neutrophil lineage withnon-segmented nuclei.They are referred to asneutrophil band cells orband forms. They areless mature thansegmented neutrophils.

An increased numberof band cells is referredto as a'left shift'.



Eosinophil

One eosinophil -mature. Normalblood - 100X.

Orange colourgranules.Bi-lobed nucleus.



Basophil

One maturebasophil.Blackish granules

overlying thenucleus.



Normal lumphocytesLymphocytes are thesmallest W BC .They have largecondensed nucleus,with a scanty bluish

cytoplasm.



Normal monocyteMonocytes are thelargest W BC .The nucleus isslightly indented .The cytoplasm isabundant, sky bluein colour.Some have vacuolesin the cytoplasm.



Red cells

Normal red cells orerythrocytes showonly slight variationin size and shape.The blood filmshould be examined

in the area wherethe red cells aretouching but not often overlapping.



Red cells

. In this area many redcells have an area of

central pallor which maybe up to a third of thediameter of the cell. Thisis consequent on theshape of a normal redcell, which resembles adisc that is thinner in thecentre.



Platelets

Normal platelets arealso apparent. Theyare small anuclearfragments betweenthe red cellscontaining smallpurple-staininggranules.



Platelet ribbon

A string of plateletsor Platelet Ribbon.

This is theappearance of normalplatelets when beingshed by amegakaryocyte into

the marrow sinus.The ribbon thenbreaks up intonumerous smallplatelet fragments.Normal blood - 100X



Platelet aggregates

P latelet aggregates maybe

composed of apparentlyintact platelets, degranulatedpale grey platelets or amixture of both, as inthis example. If theplatelet count is low it isessential to examine theblood film carefully forplatelet aggregates.



Platelet satellitism

P latelet satellitismdescribes the

phenomenon of adherence of platelets towhite cells.It is an in vitro

phenomenon of no

clinical significance.However it is important that it is detected sincethe platelet count will befactitiously low.



Nucleated epithelial cellsExtraneous non-haemopoietic cells are

sometimes seen in bloodfilms. These includeepithelial cells which arereadily identified fromtheir abundant sky-blue

cytoplasm and smallcentral nucleus. Theyare more often seenif capillary blood is

obtained by

percutaneous puncturethan when a film is



ArtefactsFixation artefact is theterm used for the

artefact that occurswhen there is water inthe methanol used forfixation of the bloodfilm.This leads torefractile rings in redcells and makes it quiteimpossible to assess redcell morphology.



Heat artefact Inadvertent heating of ablood

sample, for exampleduringtransport in a hot car, canlead to a heat artefact.R ed cells bud off

vesicles andmicrospherocytes seen.

W hite cells disintegrateand

proteins coagulate,producing weakly



Storage artefact P rolonged storage of bloodbefore making the blood film,particularly storage at roomtemperature,leads to storageartefact.W hite cells become fragile

and may form smear cells[deep red arrow].Neutrophil nuclei round up

and form homogeneousround masses or a singlemass [blue arrow].These cellshave a resemblance to N R BC .R ed cells undergo an

echinocytic change orcrenation.

blood cells morphology

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