This document summarizes red blood cell (RBC) morphology, including RBC size, hemoglobin content, shape, and inclusion bodies. Key points include variations in RBC size (microcytic, normocytic, macrocytic), hemoglobin staining properties (hypochromic, normochromic, hyperchromic), RBC shapes (sickle cells, elliptocytes, spherocytes), and inclusions (Howell-Jolly bodies, Cabot rings, Heinz bodies, malaria parasites). Clinical significance of abnormalities is provided, such as causes and associations with various diseases.

1. RBC Morphology
I. RBC Size
II. Hemoglobin Content
III. RBC shape
ken myer abansi

2. RBC Morphology RBC Size
Normal size is 6-8 u in diameter
(NORMOCYTIC RBC/ NORMAL RBC)
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ANISOCYTOSIS
→variation in RBC size
●Normocytic
●Microcytic : < 6 u
●Macrocytic : > 8 u; appear as large, mature RBC
●Megalocytic : > 10u -12u
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3. Clinical Significance (MACROCYTIC)
●Caused by increase erythropoietin
stimulation, increase synthesis of hgb
●Due to Vit. B12 and folic acid deficiency
●Cirrhosis
●Hemolytic anemia
●Pernicious anemia
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4. Clinical Significance (MiCROCYTE)
●Caused by impaired globulin
synthesis
●Decreased hgb synthesis
●Mitochondrial abnormality,
affecting synthesis of heme
●Deficiency of iron and other
building materials
●Failure of cell division or
polyploidy (kaya malaki)

5. Clinical Significance (Megalocyte)
●Due to Vit B12 and folic acid deficiency
●Failure of cell division or polyploidy (the
reason why it's big)
●Megaloblastic anemia

6. RBC Morphology HGB content
Normal: Central pallor occupies about 1/3
the size of the RBC (NORMOCHROMIC)
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ANISOCHROMATASIA
→variation in staining property of hgb
●Hypochromic : increased central pallor
●Hyperchromic: no central pallor
●Anulocyte : only periphery unstains hgb

7. RBC Morphology HGB content
Hyperchromic/Hyperchromasia/Hyperchro
●
mia
→entire cells stain deep pink and lacks central
pallor
→Clin.Sig. (does not represent true
situation, suggestive of:)
● Megalocytes of pernicious anemia
● Blood poisoning
● Acute leukemias

8. RBC Morphology HGB content
● Polychromatophilia/Polychromasia
→cytoplasm of non nucleated RBCs have a grayish
blue tint
→Basophilic material gives a diffuse homogenous blue
color
→property of rreticulocytes when stained with
Wright's
→Clin. Sig.:
● Associated with rapid RBC regeneration and increase bone
marrow activity
● Reticulocytosis
● Pernicous anemia
● Leukemia
● malaria

9. RBC Morphology HGB content
● Target cells ● RBCs show hgb conc.
→other names are At the outer rim and
– Leptocyte center
– Platycyte ● A pale circular zone
– Mexican hat separates the 2 areas
– Bull's eye ● Clin.Sig.
– Codocyte
– Hemoglobinopathies
– Liver disorders
– Iron deficiencies
– Hgb C dse
– After splenectomy

10. RBC Morphology HGB content
● Anulocyte
→Thin Rbc that are poorly hemoglobinized and
exhibit a thin peripheral ring stained hgb
● Clin.Sig.
– Hemoglobinopathies

11. Inclusion Bodies
→a normal RBC has no inclusion bodies
→RBC must be anucleated
● ARTIFACTS
→refractile areas and crenation in the RBCs
→clinical sig.
– Water in wright's stain
– Poor staining technique
– Insufficient drying of slide prior to staining

12. Inclusion Bodies
● BASOPHILIC STIPPLING
→coarse granulation resulting from RNA
aggregates
→clinical sig.
– Non specific anemias
– Lead intoxication

13. Inclusion Bodies
● CABOT RINGS
→thread like, round, oval, or figure of 8 loops
→due to residual nuclear membrane
→clinical sig.
– Pernicous anemia
– Lead intoxication

14. Inclusion Bodies
● HEINZ BODIES
→dark staining, round areas resulting from precipitated
denatured hgb
→bind to the red cell membrane and alter its rigidity ,
resulting in premature destruction in the spleen
→the spleen also removes membrane bound Heinz bodies
from red cells resulting in “blister “ or “bite” cells
→clinical sig.
– G-6-PO4 defficiency
– Heinz body anemias
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15. Inclusion Bodies
● HOWELL JOLLY BODIES
→eccentric, small, round, non refractile purple
masses consisting of DNA nuclear remnant
→clinical sig.
– Hemolytic anemia
– Post splenectomy
Number 3s

16. Inclusion Bodies
● HGB C CRYSTALS
→oblong, hexagonal in shape resulting from hgb found in
cytoplasm of RBC
→The “washington monument” or octahedral appaerance is
typical, with a clear area around the crystal. These crystals
may also be shaped like a rod, spherocytic, rhomboid, or
hexagon
→clinical sig.
– Hgb C disease : mild hemolytic anemia with
splenomegaly that is often aymptomatic but may result
in jaundice and abdominal discomfort
– Hgb SC dse

17. Inclusion Bodies
● PARASITES
→most common
→variable appearance
depending on the
parasite
→clinical sig.
– Plasmodium
infection
– Babesia infection

18. Inclusion Bodies
● PAPPENHEIMER BODIES/ SIDEROTIC
GRANULES
→small, blue granules usually appearing in clusters
near the periphery of RBC
→consists of non-iron heme
→clinical sig.
– Post splenectomy
– Sideroblastic anemia
– Sickle cell anemia

19. RBC Morphology RBC shape
● ACANTHOCYTES
→Other names
– Thorn cell(acanthol)
– Spur cell
– Spike cell
→spherical, irregularly spaced spinous processes; some have bent tip due to
membrane defect
→characterized by a progressive increase in sphingomyelin- lecithin ratio
→clinical sig.
– Abetalipoproteinemia
– Hemolytic anemia
– Neonatal hepatitis
– Liver disorders

20. RBC Morphology RBC shape
● BLISTER CELL
→contains single or multiple vacuoles on markedly
thinned areas at the periphery
→characterized by a progressive increase in
sphingomyelin- lecithin ratio
→clinical sig.
– Presence results from trauma as cells pass
through involved blood vessels

21. RBC Morphology RBC shape
● BURR CELLS
→RBCs have uniformly spaced pointed projections on
their outer edges
→clinical sig.
– Uremia
– Acute blood loss
– Cancer of the stomach
– Pyruvate kinase deficiency

22. RBC Morphology RBC shape
● CRENATED RBCs
→also known as Echinocyte (from Gk. Word echinos = sea
urchin)
→wrinkled, serrated periphery, uniform projections,
uniformly spaced bumps
→blunt spicules
→clinical sig.
– Faulty drying
– Not clinically diagnostic
– Due to dehydration, hypertonic agents,and lytic agents
– Due to exposure to anticoaguants

23. RBC Morphology RBC shape
● DACROCYTES/ TEARDROP CELLS
→fr. Gk. Word Darkry = tear
→clinical sig.
– Severe anemias
– myelofibrosis

24. RBC Morphology RBC shape
● ELLIPTOCYES/ OVALOCYTES
→has bipolar aggregates of hgb that
cause the cell to be slightly to severely
elongated instead of biconcave
→clinical sig.
– Hereditary elliptocytes
– Thalassemia
– Sickle cell anemia

25. RBC Morphology RBC shape
● KERATOCYTE
→aka Helmet cell
→irregularly contracted , triangular cells
→remnants of ruptured blister cell
→clinical sig.
– DIC (disseminated intravascular
coagulation)
– Microangiopathic anemia

26. RBC Morphology RBC shape
● KNIZOCYTE/ TRIANGLE CELLS
● →RBCs looked pinched into a triangular
shape
→clinical sig.
– Hemolytic anemia

27. RBC Morphology RBC shape
● PYKNOCYTES
→distorted, contracted RBC similar to
Burr cells
→clinical sig.
– Seen in the first 2-3 months of life
– G-6-PO4 deficiency
– Microangopathic anemia
– Hemolytic anemia
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28. ●
RBC Morphology RBC shape
SICKLE CELLS
→aka Drepanocytes, Menisocytes
→Elongated, slightly curved cells with pointed
ends
→center of cell contains a dense crystalline area
of hgb that fades somewhat towards the
periphery
→clinical sig.
– Associated with hgbs in sickle cell anemia (sca)

29. RBC Morphology RBC shape
● SPHEROCYTES
→spherical, non-biconcave (lack central pallor)
→have dark stained center instead of the normal
central pallor
→smaller surface area than the cell size; characterized by increase
osmotic fragility
→clinical sig.
– Hemolytic anemia
– HDN
– Hereditary spherocytosis (most common)

30. RBC Morphology RBC shape
● STOMATOCYTE
→ stoma or mouth aka Mouth / Stoma cell
→shows oval or rectangular (slit-like) area
of central pallor
→clinical sig.
– Liver disease
– Electrolyte imbalance
– Hereditary
stomatocytosis
– artifacts

31. RBC Morphology RBC shape
● SCHISTOCYTE
→SCHIS - cut
→fragmented RBC; a piece of the RBC is
missing causing the reultant RBC to
appear; fragmented/ distorted
→clinical sig.
– DIC (disseminated intravascular
coagulation)
– Mecahnical trauma (most common)

32. Miscellaneous
● Rouleaux Formation
→RBCs stack together
like a roll of coins
→Saline will disperse
Rouleaux
→clinical sig.
– Caused by increased
CHON (most common)
– Multiple myeloma
– Waldenstrom's
macroglobulinemia

33. Miscellaneous
● Agglutination
→Disorderly clumping of RBC
→clinical sig.
– RBC antibodies
– autoagglutinins

34. Miscellaneous
● Giant pit
→Round purple bodies
→longer than normal pit but smaller than
lymphocyte
→clinical sig.
– none

35. Qualitative Disorders of Granulocytes
● Dohle Bodies
→smear reveals pale blue staining area
within the neutrophil cytoplasm
→irregularly shaped blue staining area in
the cytoplasm due to free ribosomes or
RER
→ seen with infections
→clinical sig.
– Bacteria infection

36. Qualitative Disorders of Granulocytes
● Pyknotic nucleus
● →smear reveals neutophils with
condensed round nuclei or nuclear
fragments
→clinical sig.
– Bacterial infection
– Prolonged contact of neutrophils with EDTA

37. Qualitative Disorders of Granulocytes
● Toxic granulation
→smear reveals small dark staining granules within
the cytoplasm of neutrophils
→increased number and prominence of the
azurophilic (primary) granules
→seen most often with bacterial infections and in
association with cytoplasmic vacuolization
→clinical sig.
– Bacteria infection
– Neutrophils induced to increased production of primary
granules containing lysozymes

38. Qualitative Disorders of Granulocytes
● Toxic vacuoles
→smear reveals holes in the cytoplasm of
neutrophils
→blister cell counterpart sa RBC
→clinical sig.
– Bacteria infection
– As bacteria are digested by neutrophils , its
vacuoles appear in the cytoplasm
– Due to prolonged EDTA contact

39. Qualitative Disorders of Granulocytes
● Lupus Erythematosus cell
→smear reveals neutrophils that have
engulfed homogenous nuclear masses
→as a result, the nucleus of the
neutrophils are pushed to the periphery
of the cell
→ phagocytized nucleus occupies most
the
of the cytoplasm area
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40. Qualitative Disorders of Granulocytes
● Hypersegmentation
● →polymorphonuclear leaukocyte
normally have 3 or 4 lobes but 5/6 or
more lobes indicate hypersegmentation
→clinical sig.
– seen most often with megaloblastic
anemia , sometimes with myeloproliferative
disorders
– ff. Chemotherapy (particularly metho
trexate chemotherapy)

41. Qualitative Disorders of Granulocytes
● Smudge cell / Basket Cell
→ ruptured cell remnant , classically
a
associated with fragile lymphocyte, in CLL

42. Qualitative Disorders of Granulocytes
● Pelger-Huet anomaly
→ autosomal dominant condition with
an
neutrophils that are mostly bilobed in the
heterozygote (normal fxn ) and unilobate
in the homozygote (fatal)

43. Qualitative Disorders of Granulocytes
● May-Hegglin anomaly
→rare disorder with large prominent
Dohle like bodies
● Chediak-Higashi syndrome
→rare disorder with large neutrophilic
granules representing abnormal
lysosomes
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