Hematopathology

Peripheral Blood Film Examination Normal RBC : The normal human erythrocytes are biconcave disc, 7.2 Mm in diameter, and the thickness of 2.4 Mm at the periphery and 1 Mm in the center. The biconcave shape render the red cell quite flexible so that they can pass through capillaries whose minimum diameter is 3.5 Mm Normal red cells (normochromic): have uniformly coloured haemoglobin in side the cell with a small clear paler region in the center

Shape variation Acanthocytes with irregular, thorny speculated membrane surface projections bulbous round ends Cause: abetalipoproteinemia, renal failure, liver disease, haemolytic anaemia

Ecchinocytes: cells with 10-30 uniformly distributed spicules Cause: blood loss (acute), burns, DIC, carcinoma of stomach

Elliptocytes: have a cigar shape Cause: hereditary elliptocytosis, leukemia, thalassaemia

Sickle cells: cells have a sickle with appoint at one end Cause: sickle cell anaemia, haemoglobin S disease

Spherocytic cells: are circular ( not biconcave), smaller , more condensed than normal Cause: hereditary spheroytosis, autoimmune hemolytic anaemia, septicemia

Stomatocytes: cells are cup shaped with an abnormal area of central pallor that may be oval, elongated, or slit like Cause: liver disease, alcoholism.

Target cells: cells have an increased ratio of surface to volume Cause: iron deficiency, liver disease, haemoglopinopathies, post splenectomy

Tear drop poikilocyte: cells have teardrop or pear shape Cause: myelofibrosis, extramedullary haemopoiesis, myeloid metaplasia

Size variation: Normal: normal size ( 80- 95 ), and normal diameter (6-8u) called Normocytes Macrocytes: increase size of cells having diameter > 8 u and MCV > 95u Microcytes : decrease size of cells having diameter < 6 u and MCV < 80u

Content Of Structure Variation Basophilic stippling: appearance of fine blue dots scattered in red cells Cause: haemoglopinopathies, lead poisoning, haemolytic anaemia, myelodysplasia

Heinz bodies: are denatured particles of haemoglobin attached to RBC membrane that appear when stained with cresyl blue Cause: G6PD deficiency, drug induced

Howell jolly body: are nuclear fragment found in red cells, mostly single but sometimes multiple Cause: post splenectomy, hyposplenism

Siderocytic granules (papenheimer bodies): are cells with mitochondrial concentration of ferritin deposits The cells are stained by Prussian blue reaction Cause: disorder of iron metabolism as Sideroblastic anaemia. Postsplenectomy, burns, hemochromatosis