- Red blood cell morphology can provide clues to underlying diseases. Abnormalities include variation in size (anisocytosis), shape (poikilocytosis), color, and presence of inclusion bodies. - Microcytosis and macrocytosis indicate abnormally small or large red blood cells, seen in iron deficiency, thalassemia, and liver/bone marrow diseases. Hypochromic cells appear pale due to low hemoglobin. - Poikilocytosis describes variations in shape like elliptical, tear-drop, sickle, and fragmented (schistocyte) cells, associated with hemolytic anemias, thalassemia, and coagulation disorders. Inclusion bodies include Howell-J

1. Abnormal Red Blood Cell
Morphologies & Disease States
RED BLOOD CELLS

2. Variations in Red Blood Cell Morphology :
Size, Shape, Color and Inclusion Bodies
• Red blood cells are the major cellular component of
blood. Mature red blood cells are biconcave discs
that lack nucleus and most cell organelles such as
lysomes, endoplasmic reticulum and mitochondria.
However, variable abnormal erythrocyte morphology
is found in various pathological conditions:
• Anisocytosis: Variation in size
• Poikilocytosis: Variation in shape
• Variation in color
• Presence of inclusion bodies

3. Anisocytosis : Variation in size
• Variation of size of RBC is called anisocytosis.
The normal size of RBC is 7.5+/-0.2
micrometer in diameter. Nucleus of small
lymphocyte is useful guide to the size of RBC.
Anisocytosis is divided into Macrocytosis and
Microcytosis.

4. Anisocytosis
• Anisocytosis: is a
“generic” term used to
indicate variation in
shape of erythrocytes
(e.g. oval, pear-shaped,
teardrop-shaped,
saddle-shaped, helmet-
shaped, sickle-shaped,
and irregularly shaped).

5. Variation in size
• Microcytosis: RBCs smaller than the normal size
are considered as microcytes. Microcytosis is
seen in : Iron deficiency anemia, thalassemia,
lead poisoning, sideroblastic anemia and anemia
of chronic disorders.
• Macrocytosis: RBCs larger than the normal size
are considered as macrocytes. Macrocytosis is
seen in : Liver diseases, hypothyroidism,
megaloblastic anemia, chemotherapy, post
splenectomy and some other causes of elevated
erythropoiesis.

6. Variation in size

7. Microcytosis
• Microcytosis:
abnormally small
erythrocytes (i.e., less
than 6 in diameter).
compare with the size
for small lymphocyte.
• Found with
Hypochromic

8. Macrocytosis
• Macrocytosis:
abnormally large
erythrocytes (i.e., less
than 8 in diameter).
• Megaloblastic Anaemia
• High reticulocytes count
• Liver disease
• Myelodysplastic
syndrome

9. Variaton in color
• Variaton in color
• RBCs that appear disc shaped and having an area of
central pallor that occupies approximately one-third of
the cell’s diameter (containing normal amount of
hemoglobin) are considered as normochromic RBCs.
• Hypochromic : RBCs that have an area of pallor that is
larger than the normal are called hypochromic. This
variation is seen in : Iron deficiency anemia, anemia of
chronic diseases, thalassemia, some
hemoglobinopathies, sideroblastic anemia and any of
the conditions leading to microcytosis.

10. Poikilocytosis : Variation in shape
• Variation in the shape of RBC is called
poikilocytosis. RBCs exist as biconcave discs in
large blood vessels but their shape changes to
parachute like confirmation in capillaries.
Following are some abnormal RBC shapes :

12. Normocytic and Normochromic RBC
• Before we start with the abnormal
morphologies, let’s talk about normal
morphology of red blood cells.
• Normal mature red blood cells are biconcave ,
round discs that are about 6-8 are diameter
which is slightly smaller than the normal small
mature lymphocyte (about 6-10 in diameter.
• The term used to indicate red blood cells of
normal size and shape is normocytic

13. Normocytic and Normochromic RBC
• The term used to a normal color central pallor
(i.e., normal hemoglobin content) is
Normochromic .

14. Hypochromic RBC’s
• Erythrocytes that
demonstrate a central
pale area that becomes
larger and paler as the
hemoglobin content
diminishes.
• Iron Deficiency
• SideroblasticAnaemia
• Thalassaemia

15. Anisochromic (Normochromic plus Hypochromic)
• Anisochromic: indicates
the presence of both
normochromic and
Hypochromic

16. Polychromasia
• Polychromasia: Changeable terms used to
indicate the increased presence of non-nucleated
immature erythrocytes (Polychromatophilic
erythrocytes) that contain residual RNA which
gives a blue-gray tint to the red cells. These cells,
which remain after ejection of the nucleus from
the orthochromatic erythroblast are slightly
larger than mature erythrocytes. After exposure
to a supravital stain, the cytoplasm organelles of
these cells clump into an easily recognized blue-
staining reticulum and the cells is called a
reticulocytes.

17. Polychromasia

18. Target Cells (Codocytes)
• Target Cells (Codocytes):
erythrocytes that are thinner
than normal which show a
peripheral rim of hemoglobin
with a dark central
hemoglobin-containing area. A
pale unstained ring containing
less hemoglobin separates the
central and peripheral zones
and gives the cell a target
appearance.
• Liver Disease
• Hemoglobinopathies
• Thalassaemia
• Sideroblastic anemia

19. Spherocytes
• Spherocytes: RBCs lacks the biconcave shape
and becomes more spherical, no central pallor
is present with increased hemoglobin content.
• Spherocytes are found in : hereditary
spherocytosis, hemolytic anemia and post
transfusion reaction.

20. Spherocytes
• Spherocytes: are nearly
spherical erythrocytes
which are nearly spherical
erythrocytes which
usually have a diameter
smaller than normal.
They lack the central pale
area due to their
spherical shape.
• Hemolytic anemia
• Post transfusion
• Hereditary sphercocytosis

21. Tear-Drop Cells (dacrocytes)
• Tear-Drop Cells:
• Severe Anaemia
• Myloproliferative
disorders

22. Elliptocytes and Ovalocytes
• Elliptocytes and
Ovalocytes: are
interchangeable terms
used to indicate
ovalshaped
erythrocytes.
• Hereditary elliptocytosis
• Iron-deficiency anaemia
• Thalassaemia
• sickle cell anemia.

23. Stomatocytes
• Stomatocytes:
• Acute alcoholism
• Malignancies

24. Helmet Cells
• Helmet Cells:
• G6PD deficiency
• Pulmonary emboli

25. Helmet Cells (Keratocytes)

26. Schistocytes
• Schistocytes: are fragmented
red cell segments that are the
result of some hemolytic
process. These segments can
be a variety of shapes but
helmet cells and triangularly-
shaped cells are particularly
characteristic.
• Disseminated intra-vascular
coagulopathy (DIC)
• Thrombotic
Thrombocytopenia purpura
(TTP)
• Hemolytic uremic syndrome
(HUS)

27. Sickle cells (drepanocyes)
• Sickle cells (drepanocyes):
are interchangeable terms
used to indicate sickle-like
forms of erythrocytes
(crescent-shaped, irregular
spines, filaments, holly-leaf
appearance) noted when
RBC containing HbS are
subjected to reduction in
oxygen tension or pH.
• Sickle cell anaemia
• Sickle thalassaemia

28. Acanthocytes (Spur Cell)
• Acanthocytes (Spur
Cell):
• Congenital
abetalipoproteinemia
• Vitamin E deficiency
• Alcohol intoxication
• Post-splenectomy

29. Echinocyte (Burr Cell)
• Burr Cells:
• Liver disease
• Renal disease
• Severe burns
• Bleeding gastric ulcers
• Maybe artifact

30. Acanthocyte & Echinocyte

31. Howell-Jelly
• Howell-Jelly: are
intracellular particles
which are smooth,
round remnants of
nuclear chromatin
(DNA. Usually, only one
per cell is seen but,
occasionally, there may
be more than one
• Megaloblasticanaemia
• Mylodysplastic

32. Heinz Bodies

33. Cabot Rings
A – Cabot ring B – Howell-Jolly body

34. Basophilic Stippling
• Basophilic Stippling: is the
term used to indicate the
presence of irregular
basophilic granules in the
cytoplasm of erythrocytes.
The granules are composed
of unstable RNA and may be
fine of coarse.
• Lead Poisoning
• Thalassaemia
• Significant anaemia
• Dyserythropoiesis

35. Hemoglobin C crystals
• Hemoglobin C
crystals: are hexagonal
crystals that may be
found in individuals
with HbC syndromes.
The crystals may
intracellular or extra-
cellular.

36. Pappenheimer Bodies
• Pappenheimer
Bodies: are
intracellular inorganic
iron-containing granules
that may be ob-served
on Wright’s stained
peripheral blood
smears.

37. Rouleaux formation
• Rouleaux formation:
describes an aggregation
of erythrocytes that are
aligned one upon the
other, resembling stacks
of coins
• High level of circulating
acute-phase proteins.
• with High ESR rate.
• autoimmune conditions
• myeloma

38. Agglutination of red cells
• Agglutination of red
cells: is caused by
agglutinins and
resembles Rouleaux but
is more irregular with
round clumps rather
than linear Rouleaux

39. Summary of red blood cells
morphology