Wintrobe's Clinical Hematology 14e SC

6 Part 1: Laboratory Hematology— SECTION 1 MORPHOLOGIC ANALYSIS OF BLOOD CELLS

Preparation of Blood Smears

Blood films may be prepared on either glass slides or coverslips. Each method has specific advantages and disadvantages. 86 Blood smears are

Careful evaluation of a well-prepared blood smear is an important part

of the evaluation of hematologic disease. Although a specific diagnosis

often prepared from samples of anticoagulated blood remaining after

may be suggested by the data obtained from an automated hematology

automated hematologic analysis. However, artifacts in cell appearance and staining may be induced by anticoagulant. 7 Optimal morphology and

analyzer, many diseases may have normal blood counts but abnormal

cellular morphology. Examples of abnormal red cells that may be seen

staining are obtained from non–anticoagulated blood, most often from a

in the peripheral blood smear examination and which are associated

fingerstick procedure. Mechanical dragging of the cells across the glass

with specific disease states are found in Table 1.2 . Morphologic analysis

of the slide or coverslip and uneven distribution of blood may also distort

may be greatly hampered by poorly prepared or stained blood smears.

the cells; however, these artifacts are minimized with proper technique.

Table 1.2 Pathologic Red Cells in Blood Smears

Red Cell Type

Description

Underlying Change

Disease State Associations

Acanthocyte (spur cell)

Irregularly spiculated red cells with

Altered cell membrane lipids

Abetalipoproteinemia, parenchymal

projections of varying length and dense

liver disease, postsplenectomy

center

Basophilic stippling

Punctuate basophilic inclusions

Precipitated ribosomes (RNA)

Coarse stippling: Lead intoxication,

thalassemia

Fine stippling: A variety of anemias

Bite cell (degmacyte)

Smooth semicircle taken from one

Heinz body pitting by spleen

Glucose-6-phosphate dehydrogenase

edge

deficiency, drug-induced oxidant

hemolysis

Burr cell (echinocyte) or

Red cells with short, evenly spaced

May be associated with altered

Usually artifactual; seen in uremia,

crenated red cell

spicules and preserved central pallor

membrane lipids

bleeding ulcers, gastric carcinoma

Cabot rings

Circular, blue, threadlike inclusion

Nuclear remnant

Postsplenectomy, hemolytic anemia,

with dots

megaloblastic anemia

Ovalocyte (elliptocyte)

Elliptically shaped cell

Abnormal cytoskeletal proteins

Hereditary elliptocytosis

Howell–Jolly bodies

Small, discrete, basophilic, dense

Nuclear remnant (DNA)

Postsplenectomy, hemolytic anemia,

inclusions; usually single

megaloblastic anemia

Hypochromic red cell

Prominent central pallor

Diminished hemoglobin synthesis

Iron deficiency anemia, thalassemia,

sideroblastic anemia

Leptocyte

Flat, waferlike, thin, hypochromic cell

—

Obstructive liver disease, thalassemia

Macrocyte

Red cells larger than normal

Young red cells, abnormal red cell

Increased erythropoiesis; oval

( > 8.5 µm), well filled with hemoglobin

maturation

macrocytes in megaloblastic anemia;

round macrocytes in liver disease

Microcyte

Red cells smaller than normal

—

Hypochromic red cell

( < 7.0 µm)

Pappenheimer bodies

Small, dense, basophilic granules

Iron-containing siderosome or

Sideroblastic anemia, postsplenectomy

mitochondrial remnant

Polychromatophilia

Grayish or blue hue often seen in

Ribosomal material

Reticulocytosis, premature marrow

macrocytes

release of red cells

Rouleaux

Red cell aggregates resembling stack

Red cell clumping by circulating

Paraproteinemia

of coins

paraprotein

Schistocyte (helmet cell)

Distorted, fragmented cell; two or

Mechanical distortion in

Microangiopathic hemolytic

three pointed ends

microvasculature by fibrin strands,

anemia (disseminated intravascular

disruption by prosthetic heart valve

coagulation, thrombotic

thrombocytopenic purpura, hemolytic

uremic syndrome, prosthetic heart

valves, severe burns)

Sickle cell (drepanocyte)

Bipolar, spiculated forms, sickle-

Molecular aggregation of HbS

Sickle cell disorders, not including

shaped, pointed at both ends

S trait

Spherocyte

Spherical cell with dense appearance

Decreased membrane surface area

Hereditary spherocytosis,

and absent central pallor, usually

immunohemolytic anemia

decreased diameter

Stomatocyte

Mouth or cuplike deformity

Membrane defect with abnormal

Hereditary stomatocytosis,

Copyright © 2019 Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited. cation permeability immunohemolytic anemia Target cell (codocyte) Targetlike appearance, often Increased redundancy of cell Liver disease, postsplenectomy,

hypochromic

membrane

thalassemia, hemoglobin C disease

Teardrop cell (dacryocyte)

Distorted, drop-shaped cell

—

Myelofibrosis, myelophthisic anemia

Adapted from Kjeldsberg C, Perkins SL, eds. Practical Diagnosis of Hematologic Disorders . 5th ed. Chicago, IL: ASCP Press; 2010.

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