MLAB 1415: Hematology
Keri Brophy-Martinez
Chapter 8: Anemia
Part Two
The “Normal” RBC

Biconcave disc

Area of central pallor

Approx. size 7 µm
RBC Size Variations

Alterations in the size of the RBC is
called anisocytosis.

Correlate with MCV and RDW
3
Normocytic

MCV 80-100 fL
Macrocytes
8 μm or larger in diameter
 MCV of greater than 100 fL
 Evaluate macrocytic cells for:

◦
◦
◦
◦
shape (round versus oval)
color (red versus blue)
pallor (if present)
presence or absence of inclusions
5
Macrocytes

Macrocytes arrive in peripheral circulation by
three main ways:
◦ Impaired DNA synthesis leading to decreased number of
cellular divisions, resulting in a larger cell
 Vitamin B12/Folate deficiency
◦ Accelerated erythropoiesis ending in a premature release
of reticulocytes
◦ Conditions in which membrane cholesterol and lecithin
are increased
 obstructive liver disease
6
7
Microcytes
Diameter less than 7 μm
 MCV less than 80 fL.
 Any defect impairing hemoglobin
synthesis results in microcytic,
hypochromic RBCs.
 Decrease in hemoglobin synthesis
results in increased cellular division
and, consequently, small cells.

8
Microcytes
 Causes
◦ Ineffective iron utilization, absorption,
utilization, or release.
◦ Decreased or ineffective globin synthesis.
9
Microcyte
10
RBC Color Variations
Correlates with MCHC
 Reference range for MCHC= 32-36%

11
Normochromic

Normal hemoglobin
content

MCHC 32-36 %
Hypochromia
Any RBC having area of central pallor
greater than 3 μm.
 Direct relationship between amount of
hemoglobin in red cell and appearance of
red cell when stained.
 Any problem with hemoglobin synthesis
results in some degree of hypochromia.

13
Hypochromia
MCHC <32
 Most frequently seen in iron deficiency anemia. See in
thalassemias, hemoglobinopathies, and sideroblastic
anemias. May also see hypochromia in lead poisoning.

14
Hypochromia
Do NOT attempt to determine the presence of
hypochromia based ONLY on RBC indices – must
look at peripheral smear!
 Hypochromia usually graded (1+ to 4+).

15
Hypochromia Grading
16
Polychromasia
Occurs when immature RBCs are
released into peripheral blood stream.
 Blue-gray in color
 Larger than normal RBCs
 Basophilia is a result of residual RNA
fragments involved in hemoglobin
synthesis.

17
Polychromasia
Cells are actually reticulocytes.
 Not uncommon to find a few
polychromatic cells on a normal
peripheral blood smear.
 Reticulocyte count should reflect the
degree of polychromasia present.

18
Polychromasia

Causes of:
◦
◦
◦
◦

acute and chronic hemorrhage
hemolysis
regenerative red cell process
newborns
Excellent indicator of therapeutic
effectiveness for correcting iron
deficiency anemia or vitamin therapy.
19
Polychromasia Grading
20
Hyperchromasia

Does not exist!!!!!!
21
References
Harmening, D. M. (2009). Clinical
Hematology and Fundamentals of
Hemostasis. Philadelphia: F.A Davis.
 McKenzie, S. B., & Williams, J. L. (2010).
Clinical Laboratory Hematology . Upper
Saddle River: Pearson Education, Inc.
