Role of Peripheral blood smear examination in diagnostic work-up

Dr K Richards MD(Path);DTCDConsultant Pathologist-

HematologyYashoda Hospital

Why do a peripheral

blood film examination?

Automated hematology analysers

RBC Morphology

Anisocytosis

• abnormal erythropoiesis

• non-specific feature

• either macrocytes or microcytes or both

Poikilocytosis

• abnormal erythropoiesis

• non-specific feature• megaloblastic

anemia,• iron

deficiencyanemia,• thalassemia,• myelofibrosis,• MDS• Congenital

dyserythropoietic anemia

Microcytes

• defect in hemoglobin formation

• characteristic of iron deficiency anemia

• thalassemia• severe cases of

anemia of chronic disease

• sideroblastic anemias

Macrocytes

• classical in megaloblastic anemia

• aplastic anemia

• MDS• Alcoholics• Chronic liver disease• Hydroxyurea

Basophilic stippling

• thalassemias, • megaloblastic anemia• infections• liver disease• lead poisoning

• unstable hemoglobins• pyrimidine-5-

nucleotidase deficiency

Hypochromasia

• iron deficiency anemia

• sideroblastic anemia

• thalassemias

Dimorphic Red Cell Population

• two distinct populations

• development or resolution of IDA or anemia of chronic deficiency

• post blood transfusion• acquired sideroblastic

anemia

Spherocytes

• hereditary spherocytosis

• ABO hemolytic disease of the newborn

• autoimmune hemolytic anemia

• microspherocytes• sphero-echinocytes

Elliptocytes and Ovalocytes

• hereditary elliptocytosis

• hereditary pyropoikilocytosis

• southeast asian ovalocytosis

Schistocytes

• RBC fragments• thalassemias• CDA• Megaloblastic anemia• microangiopathic

hemolytic anemia• severe burns• hemolytic uremic

syndrome(HUS)• thrombotic

thrombocytopenic purpura(TTP)

Acanthocytes

• Abnormal phospholipid metabolism

• McLeod phenotype• Splenectomy• hyposplenism• Severe Liver disease

Crenated RBC/Echinocytes

• healthy subjects• storage artefact• uremia• cardiopulmonary

bypass• premature infants

Target Cells

• iron deficiency anemia

• thalassemia• sickle cell anemia• Hemoglobinopathies• Chronic liver disease• splenectomy• Hereditary

hypobetalipoproteinemia

Stomatocytes

• Liver disease• alcoholics• MDS

Sickle Cells

• Sickling: blood subjected to anoxia

• Sickles and boat shaped forms

• Target cells – often a feature

Rouleaux

• myelomatoses

Autoagglutination

Polychromasia

• Shades of bluish grey• Reticulocytes• Increased

erythropoiesis• Absence of

polychromasia -inadequate bone marrow response

Aplastic anemia Pure red cell aplasia

Nucleated RBCs

• More common in children• Severe anemia• Hemolytic disease of

newborn• Leucoerythroblastic

anemia:carcinomatoses and primary myelofibrosis

• Post splenectomy• Extramedullary

erythropoiesis• Sickle cell anemia • Septicemia• Cyanotic heart failure

Erythrocyte Inclusions: Howell Jolly Bodies

• Nuclear remnants• Small round, stain

purple• Post splenectomy• Splenic atrophy

Erythrocyte inclusions: Pappenheimer bodies

• Small, peripherally sited basophilic/ almost black

• Smaller than howell-jolly inclusions

• Composed of hemosiderin

• Related to Sideroblastic erythropoiesis and hyposplenism

• Confirmed by perls’ stain• Correspond to siderotic

granules of siderocytes

Morphology of Leucocytes

Toxic granulation and Cytoplasmic Vacuolation

• Bacterial infection• Other causes of

inflammation

• Administration of Granulocyte colony stimulating factor

• Poorly staining (hypogranular)

• Agranular neutrophils

• Myelodysplastic syndromes

• Some forms of myeloid leukemia

Chediak Higashi syndrome:

• Abnormal granules

• Giant but scanty azurophilic granules

• Functional defect• Susceptibility to

severe infection

Alder Reilly Anomaly:• Nucleus is obscured

by cytoplasmic granules

• Neutrophils function normally

Pelger-Huet Cells

• Benign inherited condition

• Pseudo pelger huet cells: MDS, AML with dysplastic maturation, chronic myeloid leukemia

Hypersegmented Nuclei

• Megaloblastic anemia• Uremia• Iron deficiency

anemia• Cytotoxic treatment –

methotrexate• Hydroxycarbamide

Left Shift

Basophilia

• Rarest (<1%)• Myeloproliferative

neoplasms

• CML: >10% impending accelerated phase/blast crisis

Eosinophilia• Eosinopenia: prolonged

steroid administration• Eosinophilia: - Allergic conditions, - parasitic infections, - reactive eosinophilias

( Lymphomas, ALL) - eosinophilic leukemia, - idiopathic hypereosinophilic

syndrome, - CML, - AML

Monocytes

• Chronic infections and inflammatory conditions like TB, Crohn’s disease

• Atypical CML, CMML• Acute leukemia with

monocytic component

Lymphocytes

• Transformed lymphocytes: viral and bacterial lymphocytes

• Immunoblasts or turk cells

Lymphocytes

Infectious mononucleosis:

• Activated lymphocytes

Malignant Lymphoid Cells

Circulating blasts

Platelet Morphology

Large/Giant platelets

Large Platelets:• Increased platelet

production

• Hyposplenism• Severe immune

thrombocytopenia

Thrombocytosis

• Acute inflammatory stress

• Bleeding

• Critically ill patient• Hyposplenism• Myeloproliferative

neoplasm

Grey platelet syndrome:• Hypogranular

platelets

Platelet satellitism

• antiplatelet autoantibodies

• Apparently healthy individuals

Hemoparasites

Summary

• Simple

• morphology

• Basic and foundational

• Further direction

• Patient management

References

• Dacie and Lewis practical hematology – 11th edition

• Wintrobe’s clinical hematology – 13th edition

Thank you