blood film examination
TRANSCRIPT
BLOOD FILM EXAMINATION
BLOOD FILM PREPARATIONmade on clean glass slidesFilms may be spread by hand or bymeans of an automated slide spreaderManual Method
• Hemogram:
measured and
calculated
parameters
• Histograms:
size distribution of
WBC, RBC and Plt
• Cytogram: WBC
differential
CBC on automated analyzers
Flagging for abnormalitiesnecessitates a manualPBS review
STAINING BLOOD AND BONE MARROWFILMSRomanowsky stains are used universally forroutine stainingof blood films
Giemsa’s Stain
Leishman’s Stain
Automatic staining machines are available thatenable large batches of slides to be handled
EXAMINATION OF BLOOD FILMS examined systematically
starting with macroscopic observation of thestained film assess whether the spreadingtechnique was satisfactoryand to judge itsstaining characteristics and either anyabnormal particles present
EXAMINATION OF BLOOD FILMSMicroscopic examination- progressing from low-power to high-power
Under low magnification to:(a) get an idea of the quality of the preparation(b) assess whether red cell agglutination, excessive
rouleaux formation or platelet aggregation is present(c) assess the number, distribution and stainingof the leucocytes(d) find an area where the red cells are evenly distributedand are not distorted
EXAMINATION OF BLOOD FILMSHaving selected a suitable area,
Inspection under high-power magnification
for the final examination of unusual cells and forlooking at fine details
1. RBC Size, Shape Stain Arrangement Inclusions nucleated RBCs
2. WBC Total counts Differential counts Abnormal /immature WBC
3. Platelets Counts Abnormality
4. Parasites
EXAMINATION OF BLOOD FILMS
RED CELL MORPHOLOGY
NORMAL
SHAPE - round, smooth contours
SIZE- range of 7–8 μm (about the same as that of the nucleusof a small lymphocyte on the dried film)
STAIN - Central pallor 1/3 of total area
stain quite deeply with the eosin component ofRomanowsky dyes, particularly at the periphery ofthe cell as a result of the cell’s normal biconcavity
Biconcave discDiameter : 7 - 8 μmCentral pallor occupy 1/3rd of totalSize : approx. same asnucleus of maturelymphocyte
NORMAL RED CELL MORPHOLOGY
blood film from a healthy adult
ABNORMAL ERYTHROPOIESIS
Anisocytosis- variation in size of RBCresult of the presence of cells larger than normal(macrocytosis), cells smaller than normal(microcytosis) or both; frequently bothmacrocytes and microcytes are present
Microcytes results from a defect in haemoglobin
formation
characteristic of iron deficiency anaemiavarious types of thalassaemia and severecases of anaemia of chronic disease.
Anisocytosis
AnisocytosisMacrocytes classically found in megaloblastic anaemias
also present in some cases of aplastic anaemia,myelodysplastic syndromes ,otherdyserythropoietic states, in patients beingtreated with hydroxyurea, chronic alcoholic &chronic liver disease
Poikilocytosis –variation in shape of RBC
produced in many types of abnormalerythropoiesis
for example
- megaloblastic anaemia
- iron deficiency anaemia
- Thalassaemia
- Myelofibrosis
ABNORMAL ERYTHROPOIESIS
PoikilocytosisElliptocytes and ovalocytes present when there is dyserythropoiesis
in megaloblastic anaemia (macro-ovalocytes)
in iron deficiency anaemia (‘pencil cells’)
Target Cellsrefers to a cell in which there is a central roundstained area and a peripheral rim ofhaemoglobinized cytoplasm separated by non-staining or more lightly staining cytoplasm
result from cells having a surface that isdisproportionately large compared with theirvolume
are seen in films in chronic liver diseases, irondeficiency anaemia and thalassaemia
Poikilocytosis
Sickle Cells - vary in shape between boat-shaped formsand sicklesSPICULATED CELLS AND RED CELL FRAGMENTATION
- Schistocytosis – Fragmented red cells
- Acanthocytosis- abnormality of the red cell in whichthere are a small number of spicules of inconstant length,thickness
-Stomatocytosis ,Red cell inclusion bodies- Howell–Jolly BodiesPappenheimer BodiesBasophilic stippling or punctate basophilia
Poikilocytosis
Basophillic stippling Hereditary spherocytosis
target cells
seen when there is extramedullary erythropoiesis
Tear drop cells / dacrocytes• Osteopetrosis• Myelofibrosis• Bone marrow infiltrated with
hematological ornon-hematological
malignancies• Iron deficiency anemia• Pernicious anemia
INADEQUATE HAEMOGLOBINFORMATION
Hypochromia refers to the presence of red cells that stain
unusually palely
two possible causes: a lowered haemoglobinconcentration and abnormal thinness of thered cells
Hyperchromasia (Hyperchromia) deep staining of the red cells with a lack of
central pallor
seen in two circumstances
- in the presence of macrocytes
- cells are abnormally rounded
Abnormally rounded cells may be eitherspherocytes or irregularly contracted cells
Spherocytosis cells that are more spheroidal (i.e. less disc like)
than normal red cells but maintain a regularoutline
diameter is less and thickness is greater thannormal
result from genetic defects of the red cellmembrane as in hereditary spherocytosis,haemolytic anaemia
Anisochromasia-
Dimorphic Red Cell Population abnormal variability in staining of red with two
distinct populations
is characteristic of a changing situation
It can occur during the development or resolutionof iron deficiency anaemia
Polychromasia
Blue-gray coloration of RBCS.Due RNA remnants
Increased - Increased erythropoieticactivity. Decreased - Hypoproliferativestates.
Hemolytic anemias•Blood loss anemias•Recovering anemia
Hypochromic MicrocyticAnaemia
Iron deficiency Anaemia
Thalasemia
Anemia of chronic disease
Iron deficiency anemia
Iron deficiency anemia
Hypochromic microcytic anemia of irondeficiency (peripheral blood smear)
Examination of peripheral blood film
RBC shows Hypochromic Microcytic anaemia withmoderate anisocytosis & poikilocytosis with thepresence of elliptical forms, elongated pencilshaped cells
WBC - white cell count and differential are normal
Platelet - normal
Comment: Hypochromic Microcytic anaemia
Differential diagnosis: Iron deficiency anaemiaThalasaemia
Investigation of a microcytic hypochromicanaemia
Microcytosis Macrocytosis Target cells Spherocytes Red cellfragments
Nucleatedred blood Howell-Jolly body
Basophilic stipplingPolychromasiaabnormal ribosomal RNA appears asblue dots
Shows marked anisocytosis, marked poikilocytosis,one unusually large macrocyte and one severelyhypochromic cell
Blood film showing macrocytes, oval macrocytes & ahypersegmented neutrophil
Blood film showinghypochromia, microcytosis and poikilocytosis
Investigation of a macrocytic anaemia