Week 6: Cell Morphology

• Wright stain

• RBC morphology

• Anisocytosis

• Poikilocytosis

• WBC morphology

• WBC differentials

• Artifacts

Wright Stain

• Romanowsky stain family

• Polychromatic

• Absolute methanol fixative

• Methylene blue - basophilic components

• Eosin - acidophilic components

Smear Making

• Essential in morphology

• Wedge method

• Thickness and length

Key Features

• Size

• Nuclear shape

• Chromatin features

• Granules and other inclusions

• Color

Leukocytes

• Granulocytes: have specific granules• Eosinophil

• Basophil

• Neutrophil

• Non-granulocytes• Lymphocyte

• Monocyte

Granulocytes

• Eosinophil• Large orange

granules

• <2% in circulation

• Usually bilobed

• Increased in allergy, parasites

Granulocytes

• Basophil• Large black-purple

granules

• <1% in circulation

• Increased in allergy, CML

Granulocytes

• Segmented Neutrophil• Small purple granules• 54-62% in circulation• Coarse chromatin• Increased in bacterial

infection

• Band• No nuclear filament• 3-5% in circulation• Increased in bacterial

infection

Non-Granulocytes

• Lymphocyte• Relatively small

• Round or oval nucleus

• Smudged chromatin

• Basophilic cytoplasm

• Increased in viral infection

• 25 - 33% (more in children)

Non-Granulocytes

• Monocyte• Relatively large

• Grey cytoplasm with vacuoles

• Irregular nucleus

• Linear chromatin

• Increased in chronic infection

• 3 - 7%

Platelets

• Cytoplasmic fragments of large megakaryocyte

• 2-3 m in diameter with granules

• Promotes clot formation

• 8-20 per oil immersion field

• 150,000 - 400,000/L

Erythrocyte Morphology

• Normal: biconcave disc of 7.5 m diameter

• Has central pallor (1/3 of diameter) on smear

• No inclusions

Good Area to Evaluate Morphology

Anisocytosis: Variation in Size

Microcytes Macrocytes

Poikilocytosis: Abnormal Shape

Target Cells Hypochromic

Poikilocytosis

Sickle Cell Schistocyte

Poikilocytosis

Teardrop Cell Spherocyte

Poikilocytosis

Elliptocyte Stomatocyte

RBC Inclusions, etc.Polychromasia Howell-Jolly Bodies

RBC InclusionsCabot Ring Basophilic Stippling

RBC Inclusions, etc.

Rouleaux Malaria

Too Thick

Too Alkaline

Too Thin

Too Acidic

Unacceptable Slides