WHITE CELL AND PLATELET MORPHOLOGY

Myeloid series

MyeoblastThese are the most immature cells of the granulocyte series. They are usually large (12-20microns). Cytoplasm: is scanty and stains a bright blue at the edges/margin.Granules: there may be none or some fine azurophilic granules can be observed.Nucleus: generally it is round with delicate lace like chromatin with nucleoli 1-2+ present.

PromyelocyteThese are usually larger than myeloblasts (12-23microns). The N:C ratio decreases. Cytoplasm: usually there is plentiful with coarse aurophilic primary granulesNucleus: is oval and tends to lie eccemtrically in cytoplasm with a delicate chromatin and sometime 1 nucleoli. The chromatin however may be slightly denser than a myeloblast.

MyelocyteSmaller than promyelocyte (12-20microns) Cytoplasm: is bluish but turns pinker as it matures. The coarse aurophilic granules disappear and fine neutrophil granules are seen.Nucleus: is smaller and round with the chromatin clumping. No nucleoli are seen

MetamyelocyteThe cytoplasm may be similar to the above the main difference is in the nucleus where there is slight indentation (kidney shapped)

BandSeen in the peripheral blood in infections and inflammation. When a large percent of these are present a left shift term is used for neutrophil maturation

NeutrophilThey are a phagocytic cell that is particularly affective at fighting bacterial infections. They are the first responders to inflammation migrating through the blood, blood vessels, into interstitial tissueNeutropenia: congenital, aplastic anaemia, leukaemia, side effect of medication that causes margination, sepsis overwhelmed.

EosinophilResponsible for combating multicellular parasites and certain infections. Along with mast cells they are important and associated with allergy and asthma.Love acid and therefore take up eosin. Their granules are histamine and proteins. Eosinophilia: parasitic infection, collagen vascular disease (rheumatoid arthritis), malignant disease (hodgkins diseas), extensive skin disease, addisons disease, penicillin. asthma

BasophilIs stained by basic dyes and functionally has a role in mediating hypersensitivity reactions of the immune system. They synthesis histamine and modulate inflammatory response. When IgE binds to the receptors on a basophil the cell releases histamine, serotonin and leukotrienes. These constricting, causing skin flush and hives.

MonocyteLarge mononuclear phagocytes. They are the immature stage of a macrophage. Monocytes are increased in chronic inflammatory disease, leukaemia, parasitic infection, TB, and IM

Lymphoid series

LymphoblastThese are commonly seen in ALL and morphologically are classified into 3 subtypes.The nuclei are round-oval with coarse chromatin, aggregating into masses. The nucleoliis small and inconspicuous. The cytoplasm is very basophilice, sparse in volume without granules (never ever ever seen auer rods)

ProlymphocyteIn the lymphocytic series it is the intermediate between the lymphoblasts and the lymphocyte the cytoplasm is less blue and the chromatin is more condensed. However there are prominent nucleoli still visible.Increased prolymphocytes are seen in leukaemias such as CLL, ALL, PLLThe nucleus has coarser chromatin structure than lymphoblast however its chromatin is not clumped like a lymphocyte, it may be granular.

LymphocyteIncreased in: chronic bacterial infections, infectious heapatitis. IM, lymphocytic leukaemia. Multiple myeloma, viral infection

Decreased in: chemo, HIV infection, leukaemia, sepsis, steroid use

Chromatin is clumped and smudgey

Plasma CellPlasma cells vary from 8-20microns. They have round eccentrically placed nucleus with dense chromatin patterns. The cytoplasm is basophilic with a peri-nuclear halo.

Neutrophil Changes

Toxic granulationThis appears as dark blue granules in the cytoplasm of neutrophils. These granules are thought to be primary granules.

VacuolationSeen as a toxic change when a person is infected with a bacterial infection. This is a common feature of sepsis and DIC

Dohle BodiesAre light blue-grey oval basophilic leukocyte inclusions that are located in the peripheral cytoplasm of neutrophils. They are most likely remnants of rough ER and are seen in toxic changes

DegranulationThe process of releasing antimicrobial cytotoxic molecules/ granules into the surroundings

Auer RodsThey are clumps of azurophilic granular materal that form elongated needle like structures in myeloid leukaemic blasts.

Hypersegmentation Normally the neutrophils have 2-3 lobes however in the case of hypersegmentatin there are 4-5 + lobes, This is seen in megaloblastic anaema, MDS and heavy metal poisoning.

Pelger-Heut anomalyThe Neutrophils are segmented only into two lobes and the nuclear chromatin is condensed forming a large clump. The lobs are round-oval and are joined by a thin nuclear connection. This is seen in the genetic condition but a pseudo form is seen in MDS.

Intracellular organisms

Abnormal changes/forms in Lymphoid cells

Hairy cell

Smear cellWeak cell has smudged in the process of film making. Seen in IM, leukaemia and viruses.

Atypical cellLarge cells where the cytoplasm stains darkly and the nucleus is eccentric. Sometimes they look to have a nucleoi. They are often seen scalloping RBC in cases where the patient is infected with IM

Reactive cells Deep blue cells with high N:C ratio

Lymphoma cell

Large granular cell

Platelets

ThrombocytosisThis can be reactive due to surgery or recent bleeding. It can also be seen in MPN such as ET and PV

ThrombocytopeniaThis can be seen in conjunction with giant platelets. Need to look out for dropping platelet counts in pregnant women. But also can be seen in MDS (with other cytopenia), viral infections, DIC, etc

Giant Platelets Seen when people are pushing out platelets early due to low platelet counts, or if there has been a recent bleed and in some malignancies

SatellitismThis is seen due to EDTA artefact

Platelet clumpingEDTA artefact

Micro-megakaryocyteThey are seen in the blood in MDS