Pappenheimer bodies are noniron basophilic granules contained in the ironprotein matrix and stain positive for iron in the presence of noniron stains. Ferritin is normally absent in RBCs. During hemoglobin formation, in the premature infant and newborn, siderocyte free-iron granules commonly occur in developing normoblasts and reticulocytes. The presence of

 

Method

¾ Place I volume of filtered stain in small test tube

¾ Place I volume of capillary or venous blood and mix

¾ Incubate at room temperature or at 37°C for 10–30

minutes

¾ Remix the tube contents and spread 1 drop of the

stained blood on a slide making a thin film.

When dry, examine with the oil immersion lens. Count

systematically at least 500 cells, including in this the

number of reticulocytes. Reticulocytes appear larger than

mature cells and contain irregular dark purple granules

or fine threads of ribonuclear material, calculate the

percentage of retikulocytes.

Interpretation: Reticulocyte counts are low in ineffective

erythropoiesis, e.g. myelosclerosis, aplastic anemia,

megaloblastic anemia, thalassemia, erythroleukemia and

sideroblastic anemia. Reticulocytosis occurs after blood

loss or effective therapy for certain kinds of anemia, e.g.

therapy of iron deficiency or megaloblastic macrocytic

anemia. Reticulocytosis also occurs in hemolytic anemias.

236 Concise Book of Medical Laboratory Technology: Methods and Interpretations TABLE 9.2: Various RBC abnormalities and their possible causes

Description of abnormalities of RBC color Possible causes of abnormal RBC color

Anisochromia is demonstrated by variable staining intensities indicating

unequal hemoglobin content due to multiple populations of red blood cells

(RBCs)

Anisochromatism: Iron-deficiency anemia treated with transfused blood

Hyperchromia is demonstrated by the presence of cells having a smaller than

normal area of central pallor, causing the cells to take on excessive staining

and demonstrate higher than normal pigmentation. Increased amounts of

these cells are called hyperchromatism

Hyperchromatism: Dehydration, increased bone marrow iron

stores, inflammation (chronic), and in the presence of spherocytes that have increased cell wall thickness

Hypochromia is demonstrated by the presence of cells having a larger than

normal area of central pallor, causing the cells to stain weakly and appear to

have less than normal pigmentation. Increased amounts of these cells are

called hypochromatism

Hypochromatism: Anemia (iron deficiency) and decreased

hemoglobin concentration

Polychromatophils are cells that are stainable with many types of stains, such

as stains with both an acid and base component. They are demonstrated by

a bluish-pink tinge caused by the presence of both hemoglobin stained by

acid and cytoplasmic ribonucleic acid (RNA) stained by the basic component.

Both the larger-than-normal cell size and the presence of cytoplasmic RNA

indicate that polychromatophils are reticulocytes (newly made RBCs).

Increased amounts of polychromatophils is called polychromatosis and

occurs in accelerated RBC production

Polychromatosis: Hemorrhage, hemolysis, reticulocytosis, and

therapy for iron deficiency anemia or pernicious anemia

Description of abnormalities of RBC shape Possible causes of abnormal RBC shape

Acanthocytes are cells with irregular, thorny, spiculated membrane surface

projections containing bulbous, rounded ends. They result from an irreversible defect in the lipid content of the RBC membrane. The presence of acanthocytes is called acanthocytosis

Acanthocytosis: Abetalipoproteinemia (most common cause),

alcoholic cirrhosis, hemolytic anemia (induced by pyruvate

kinase deficiency), hepatic disease, postsplenectomy, and

retinitis pigmentosa. Drugs include heparin calcium and

heparin sodium.

Crescent bodies (achromocytes) are cells with a faint quarter-moon shape

caused by RBC rupture

Achromocytosis: Any condition that increases the fragility of

RBCs (i.e. sickle cell anemia, reduced oxygen supply)

Drepanocytes/sickle cells are cells formed in the shape of a sickle with a point

at one end. The presence of these cells is called drepanocytosis

Drepanocytosis: Anemia (hemolytic, sickle cell) and hemoglobin SC disease

Echinocytes/burr cells/crenated: RBCs have a cell surface with 10–30

uniformly distributed, blunt spicules. Echinocytes may be commonly due

to pH changes due to faulty drying during smear preparation, but certain

physiologic conditions, including a reversible defect in the lipid content of

the RBC membrane, have been associated with their presence. The presence

of these cells is called echinocytosis

Echinocytosis: Bile acid abnormalities, blood loss (acute),

burns (extensive), carcinoma of the stomach, disseminated

intravascular coagulation (DIC), gastric ulcers (bleeding),

increased free fatty acids, microangiopathic hemolytic

anemia, pyruvate kinase deficiency, renal failure, thrombotic

thrombocytopenic purpura, and uremia. Drugs include

barbiturates, heparin calcium, heparin sodium, and salicylates

Elliptocytes/ovalocytes have a cigar shape, which distinguishes them from the

more oval shape of the ovalocytes. They are normal constituents of mature

RBCs. Higher than normal amounts of these cells are called elliptocytosis

Elliptocytosis: Anemias (iron deficiency, pernicious, sickle

cell), hereditary elliptocytosis, leukemia, megaloblastic

hematopoiesis, and thalassemia

Leptocytes/target cells have an increased ratio of surface to volume, often

due to a shape that looks like a cup, bell, or hat. They have a colorless center

and are thinner and lighter staining than normal RBCs due to abnormally

low amounts of hemoglobin. When stained, the depth of the “cup” collapses,

causing a bulls-eye appearance. The presence of leptocytes is termed

leptocytosis

Leptocytosis: Anemia (iron deficiency, sickle cell), cellular

dehydration, cirrhosis, hemoglobin C disease, hemoglobin SC

disease, hepatitis, jaundice (obstructive), postsplenectomy

and thalassemia

Contd...

Clinical Hematology 237

Contd...

Contd...

Description of abnormalities of RBC shape Possible causes of abnormal RBC shape

Poikilocytes occur in varying shapes, ranging from slightly irregular to

dumbbell-like, pear-shaped or teardrop-shaped. Defective bone marrow

production causes poikilocytosis, a general term used to describe the

presence of cells demonstrating variation from the normal shape of the RBC

Poikilocytosis: Anemia (iron deficiency, hemolytic,

megaloblastic. pernicious), myelofibrosis, myeloid metaplasia,

and thalassemia

Schizocytosis/schistocytes are RBCs with adhesions of spiral and triangular

RBC fragments due to hemolysis, hemoglobinopathies, or erythrocytic

mechanical damage from fibrin strands. The presence of these cells is called

schizocytosis

Schizocytosis or Schistocytosis: Anemia (acute hemolytic,

microangiopathic hemolytic), burns (severe), disseminated

intravascular coagulation (DIC), prosthetic heart valves,

pyruvate kinase deficiency, renal graft rejection, uremichemolytic syndrome, valve prosthesis and valvular stenosis

Spherocytes are cells that are globe-like rather than biconcave, with an

abnormally small dimple. They are thicker than normal, with many fineneedle-like projections. Spherocytes lack an area of central pallor (due to an

increased mean corpuscular hemoglobin concentration) and have a smaller

surface area relative to their size. Spherocytes are caused by mechanical

fibrin strand damage to circulating RBCs. The presence of spherocytes is

called spherocytosis

Spherocytosis: ABO hemolytic disease of the newborn,

accelerated reticuloendothelial RBC destruction, anemia

(hemolytic), following blood transfusion, hereditary

spherocytosis, and thermal injury of the cell membrane

Stomatocytes are cup-shaped RBCs with an abnormal area of central

pallor that may be oval or rectangular elongated, or slit-like. These cells are

produced by antibodies or hydrocytosis. The presence of these cells is called

stomatocytosis

Stomatocytosis: Alcoholism, cirrhosis, erythrocyte sodium

pump defect, hepatic disease (obstructive), hereditary

spherocytosis, hereditary, stomatocytosis, and Rh null cells

Description of abnormalities of RBC size Possible causes of abnormalities of RBC size

Anisocytosis is a general term that describes any variation in the size of the

RBC

Anisocytosis: Anemias (iron deficiency, pernicious), folic

acid deficiency, following blood transfusion of normal cells

into an abnormal RBC population, leukemia, newborns, and

reticulocytosis

Macrocytes are large erythrocytes having a diameter > 8 µ, a mean corpuscular

volume > 96 µ, and higher than normal hemoglobin content. They are usually

increased due to stress erythropoiesis. Increased amounts of macrocytes are

called macrocytosis

Macrocytosis: Anemia (hemolytic, pernicious), folic acid

deficiency, following hemorrhagic states, hepatic disease,

hyperthyroidism, idiopathic steatorrhea, newborns,

reticulocytosis, and thalassemia

Microcytes have an RBC diameter <6 µ, a mean corpuscular volume <76 µ,

and mean corpuscular hemoglobin concentration <27%. Increased amounts

of microcytes are called microcytosis

Microcytosis: Anemia (from chronic hemorrhage, iron

deficiency), hemoglobinopathies, hereditary spherocytosis,

and thalassemia.

Description of abnormalities of RBC content of structure Possible causes of abnormal RBC content of structure

Agglutination: Clumping together of RBCs is an immune mechanism caused

by antibody formation

Agglutination: Invading antigen(s)

Basophilic stippling is demonstrated by the presence of minute basophilic

granules that cause a bluish/purple color when reticulocytes are stained.

They are caused by ribosomal aggregation that occurs as smears are

prepared. Small amounts of basophilic stippling normally occur as the

smears are dried. Increased amounts occur in conditions in which RNA has

aggregated in the cells

Increased basophilic stippling: Alcoholism, anemia

(megaloblastic, sickle cell), heavy metal intoxication (bismuth,

lead, mercury, and silver), hemorrhage (gastrointestinal),

leukemia, and thalassemia

Cabot’s rings are cells containing mitotic spindle remnants appearing as fine,

threadlike filaments of bluish purple color in the shape of a single ring or a

double ring (figure-eight shape)

Presence of Cabot’s rings: Anemia (severe, pernicious), lead

poisoning, myelofibrosis, and myeloid metaplasia

238 Concise Book of Medical Laboratory Technology: Methods and Interpretations Contd...

Contd...

Description of abnormalities of RBC content of structure Possible causes of abnormal RBC content of structure

Heinz bodies are denatured particles of hemoglobin attached to the RBC

membrane that appear when stained with cresyl blue or new methylene blue.

Heinz bodies usually indicate abnormal erythrocyte stability due to hemolytic

conditions or hemoglobinopathies

Presence of’Heinz bodies: Alpha-thalassemia, anemia

(hemolytic), glucose-6-phosphate dehydrogenase

deficiency, hemoglobinopathies, methemoglobinemia, and

post-splenectomy. Drugs include analgesics, antipyretics,

chlorates, phenacetin, phenothiazines, phenylacetamide,

phenylhydrazine phenylamine, primaquine phosphate,

resorcinol, and sulfapyridine

Howell-Jolly bodies are nuclear fragments contained in red cells that stain

purple or violet. They are normally present in immature RBCs and in mature

erythrocytes before they pass through the splenic circulation. In conditions

causing increased RBC production, erythrocytes contain higher than normal

amounts of these bodies

Presence of Howell-Jolly bodies: Anemia (hemolytic,

megaloblastic), leukemia, splenic absence congenital or surgical removal), and splenic atrophy

Platelets on RBCs appear as a halo that resists staining and can be easily

confused with RBC inclusion bodies

Rouleaux formation is demonstrated by a cellular configuration in stacks or rolls.

Increased rouleaux formation may be caused by increased fibrinogen or globulins in the blood. Rouleaux formation is decreased by the presence of abnormally

shaped RBCs, which inhibits adherence of the cells in a stacked shape. Rouleaux

formation may also result from a delay in slide preparation

Increased rouleaux formation: Hyperfibrinogenemia,

macroglobulinemia, and multiple myeloma

Decreased rouleaux formation: Hereditary spherocytosis

Siderocytes/Pappenheimer bodies are cells with mitochondrial concentrations

of ferritin (nonhemoglobin iron) deposits. These cells stain as purple-bluish

granules only in the presence of iron stains such as Prussian-blue reactions.

Pappenheimer bodies are noniron basophilic granules contained in the ironprotein matrix and stain positive for iron in the presence of noniron stains.

Ferritin is normally absent in RBCs. During hemoglobin formation, in the

premature infant and newborn, siderocyte free-iron granules commonly

occur in developing normoblasts and reticulocytes. The presence of

siderocytes is called siderocytosis

Siderocytosis/Pappenheimer bodies: Anemia (chronic hemolytic, congenital spherocytic, dyserythropoietic, megaloblastic, pernicious, refractory, sideroblastic), burns (severe),

hemochromatosis, infection, lead poisoning, postsplenectomy, and thalassemia

Red blood cell abnormalities seen on stained smear (in brief)

Descriptive term Observation Importance

Macrocytosis Cell diameter > 8 µm

MCV > 96 fl

Megaloblastic anemias, severe liver disease

Hypothyroidism

Microcytosis Cell diameter < 6 µm

MCV < 76 fl

MCHC < 27

Iron deficiency anemia

Anemia of chronic disease

Thalassemia

Hypochromia Increased zone of central pallor Reduced Hb content

Polychromatophilia Presence of red cells not fully hemogolobinized Reticulocytosis

Poikilocytosis Variability of cell shape Sickle cell disease

Microangiopathic hemolysis

Extramedullary hematopoiesis

Marrow stress of any cause

Clinical Hematology 239

Descriptive term Observation Importance

Anisocytosis Variability in cell size Reticulocytosis

Transfusing normal blood into microcytic or

macrocytic cell population

Leptocytosis Hypochromic cells with small central zone

Hb (target cells)

Thalassemias

Iron deficiency anemia, obstructive jaundice

Spherocytosis Cells without central pallor, loss of biconcave

shape MCHC high

Loss of membrane relative to cell volume.

Hereditary spherocytosis.