MLAB 1415: Hematology
RBC Morphology on a
Peripheral Blood Smear
Laboratory: RBC Morphology on a Peripheral Blood Smear
Skills= 20 pts
Objectives:
1. Identify examples of abnormal red blood cell (RBC) morphology and inclusions.
2. To determine within one qualitative unit the abnormal red blood cell morphology observed
on a peripheral blood smear.
Principle:
Peripheral blood smears are evaluated to determine cell morphology, verify automated cell counts,
and determine the percentage of each type of WBC. Today’s lab focuses on identifying red blood
cell inclusions and abnormal RBC morphology.
Reagents, Supplies, and Equipment:
1. Prepared slides
2. Microscope, immersion oil and lens paper
Procedure:
1. Place a Wright stained slide on stage.
2. Using the 10X objective, find an area where 50% of the RBCs are slightly overlapping and
50% of the RBCs are not touching (toward the feathered edge). The red blood cells
should have a central pallor. Avoid areas where holes in the blood smear are seen or the
RBCs look flat, large and distorted. Also, avoid thicker areas of the smear where the
RBCs appear to have rouleaux.
3. Using the turret, switch to the 100X oil objective, add oil, and focus on the red blood cells.
4. In at least 10 consecutive fields, observe the number of inclusions, and/or examples of
abnormal RBC morphology. If abnormalities are observed, calculate the average number
observed per field.
5. Semi-quantitate any variation from normal morphology using the tables below.
6. If no significant RBC morphology is seen, report RBC morphology as “Normal”.
7. Record results on results form below.
8. Repeat with a second slide.
MLAB 1415: Hematology
RBC Morphology on a
Peripheral Blood Smear
Procedural notes:
RBC inclusions and morphology definitions
Variation Abnormality
Description
Anisocytosis
Variation in RBC size
Poikilocytosis
Variation in RBC shape (clarify particular
variation such as 1+schistocytes, 2+ codocytes)
Abnormal Size
Description
Microcytosis
Abnormally small RBC with MCV <80fL and
diameter less than 7.0 µm
Macrocytosis
Abnormally large RBC with MCV >100fL.
Abnormal Color
Hypochromia
Polychromasia
Abnormal Shape
Echinocyte or Burr Cell (Crenated RBC)
Drepanocyte (Sickle cell)
Schistocyte or schizocyte (cell fragment)
Description
Enlarged area of pallor due to cell’s decreased
hemoglobin content
Bluish/purple hue in young RBCs due to
residual RNA
Description
RBCs with many blunt spicules. This can be
caused by biologic reasons (uremia, Vit. E
deficiency abetalipoproteinemia, postsplenectomy) or artifactual (slow drying, old
RBCs, in thick area of slide). Do not grade
these cells in the thick area of the slide.
Elongated cell with point on each end; may be
curved or S-shaped.
Fragmented erythrocyte in many shapes and
sizes; can display pointed extremities
HELMET CELL (bite cell)
Special schistocyte; Results from RES taking a
“bite” out of RBC. Looks like 1920s football
helmet.
Codocyte (target cell)
Bull’s eye looking RBC. Central concentration
of hemoglobin surrounded by colorless area
with peripheral ring of hemoglobin. May also be
bell or cup shaped. See atlas.
MLAB 1415: Hematology
Dacryocyte (Tear drop cell)
Stomatocyte
RBC Morphology on a
Peripheral Blood Smear
RBC shaped like a tear or pear. Before
reporting make sure that they are not artifactual
due to slide preparation (all pointing same
direction)
RBC with slitlike (smile) area of central pallor.
Acanthocyte (spur cell)
RBC with irregularly spaced projections that
vary in width, length and number.
Elliptocyte or Ovalocyte
Ellipto: cigar-shapped RBC
Ovalo: egg-shaped RBC
Spherocyte
Inclusions
Hemoglobin C crystal
Small, globular, completely hemoglobinated
RBC without central pallor
Descriptions
Dark red hexagonal RBC inclusion
Basophilic stippling
Bluish-black granules (Wright’s stain) in RBCs
from precipitating ribonucleoproteins and
mitochondrial remnants in toxic states (lead
poisoning)
Howell-Jolly bodies
Dark purple spherical granule near periphery of
RBC composed of remnants of DNA
Pappenheimer bodies
Cluster of iron-containing particles usually found
at the periphery of mature RBCs
Malaria
Arrangement
Rouleaux
Agglutination
Can appear as rings within RBC
Descriptions
Stacked coin appearance of RBCs (in the
examining area of the smear)
Clusters of RBCs due to presence of a coldacting antibody against red cells
MLAB 1415: Hematology
RBC Morphology on a
Peripheral Blood Smear
RBC Morphology Grading System/hpf (100X oil)
Abnormality
Anisocytosis
Poikilocytosis
Slight
1+
2+
3+
<15%
Variation Abnormality
15-25%
26-49%
<1
If > SLT, Grade each type of abnormal shape
50-89%
Abnormal Size
OCC/Few
Without CBC:
25% smaller than
nucleus of small lymph
Without CBC:
26-49% smaller
than nucleus of
small lymph
Without CBC:
≥50% smaller
than nucleus of
small lymph
MCV 75-79
MCV 70-75
MCV <70
Without CBC:
25% larger than
nucleus of small lymph
Without CBC:
26-49% larger
than nucleus of
small lymph
Without CBC:
≥50% larger than
nucleus of small
lymph
MCV 100-150
MCV 105-110
MCV >110
Without CBC:
25% larger area of
central pallor
Without CBC:
26-49% larger
area of central
pallor
Without CBC:
≥50% larger area
of central pallor
2
MCHC 28-31
3-4
MCHC 24-27
5-7
<24
>8
<1
Abnormal Shape
1-3
4-5
>5
1-2
3-4
5-7
≥8
<1
1-3
4-5
>5
<1
1-3
4-5
>5
<1
1-3
4-5
>5
<1
1-3
4-5
>5
<1
<1
1-3
1-3
4-5
4-5
>5
>5
2
3-4
5-7
>8
Microcytosis
OCC/Few
Macrocytosis
4+
Reserved for
extreme
cases where
90-100% of
the cells are
abnormal
Abnormal Color
Few
Hypochromia
Polychromasia
Echinocyte or Burr
Cell (Crenated
RBC)
Codocyte (target
cell)
Schistocyte or
schizocyte (cell
fragment)
Helmet cell
(bite cell)
Drepanocyte
(Sickle cell)
Dacryocyte (Tear
drop cell)
Stomatocyte
Acanthocyte (spur
cell)
Elliptocyte or
Ovalocyte
Reserved for
extreme
cases where
90-100% of
the cells are
abnormal
MLAB 1415: Hematology
Spherocyte
2
RBC Morphology on a
Peripheral Blood Smear
3-4
5-7
>8
Inclusions
<1
1-3
4-5
>5
Basophilic stippling
<1
1-3
4-5
>5
Howell-Jolly bodies
<1
1-3
4-5
>5
<1
1-3
4-5
>5
Rouleaux
<10%
Agglutination
<10%
Arrangement
10 -25%
10 -25%
25%-50%
25%-50%
≥50%
≥50%
Hemoglobin C
crystal
Pappenheimer
bodies
MLAB 1415: Hematology
RBC Morphology on a Peripheral Blood Smear
Name: _________________
Date:__________________
Laboratory: RBC Morphology on a Peripheral Smear
Report Form
20 pts
Slide # or Patient
Name
Abnormal variation
(aniso/ poik)
Abnormal Size
Abnormal Shapes
Inclusions/ RBC
Color
MLAB 1415: Hematology
RBC Morphology on a
Peripheral Blood Smear
Name: _________________
Date:__________________
Laboratory: RBC Morphology on a Peripheral Smear
Study Questions
11 pts.
1. Poikilocytosis is the term for variation in _________________.
2. Microcytes are defined as having an MCV less than ____________.
3. Howell-Jolly bodies are composed of ________________.
4. According to the ACC RBC morphology grading scheme, if an average of 7 bluish-purple
young RBCs were observed in 10 100x/oil fields, what morphology abnormality would you
document and how would you grade it? (2pts)
5. According to the ACC RBC morphology grading scheme, if an average of 40% of the
RBCS in 10 100x/oil fields had a significantly larger than normal central pallor, what
morphology abnormality would you document, and how would you grade it? (2pts)
6. Pappenheimer bodies are composed of __________.
7. A schistocyte is also known as a cell ______________.
8. A sickle cell is also known as a ____________.
9. What causes agglutination on the blood smear?