Lecture 14 RBC Morphology Flashcards
1
Q
Rouleaux
A
- linear arrangement of at least four red cells
- must be in thin area
- seen in infections, inflammations, multiple myeloma (increased plasma proteins)
- plasma proteins (+ve) net negative charge from sialic acid -> no longer repel each other
- corresponds to elevated ESR
2
Q
RBC cold agglutinins
A
- interfering substance in automation
- caused by Pt’s autoantibody which reacts at cold temp -> RBCs agglutinate
- warm sample to 37 deg C
does not occur in circulation
3
Q
Normochromic
A
- diameter of pallor less than 1/3 of RBC diameter
- gradual increase of Hgb from interior towards outside
4
Q
Hypochromic
A
- Pallor greater than 1/3 of cell diameter
- decreased Hgb conc
- associated with microcytosis
- seen in iron deficiency anemia (IDA)
5
Q
Dimorphism
A
- two populations of cells
- histogram will show 2 peaks
- hypochromic and normochromic cells present
- seen in sideroblastic anemias, after blood transfusion treatment of IDA patients
6
Q
Normocytic
A
- normal diameter 6-8um (avg 7 um)
- avg volume 90 fL
- same size or slightly smaller than lymphocyte nucleus
7
Q
Macrocytic
A
- diameter exceeds 8.5-9 um
- MCV > 100 fL
- round macrocytes seen in neonates, alcoholism, liver disease, B12 and folate deficiency
- oval forms seen in B12, folate deficiency, and myelodysplastic syndromes
8
Q
Polychromatic Cells
A
- immature RBCs w/o nucleus, diffusely pale blue due to remnants of RNA
- can be stained with new methylene blue -> RNA precipitate -> reticulated appearance -> called reticulocytes
- small numbers normal
- increase from hemolysis
- decrease from metabolic of nutrient deficiency (B12 or folate)
9
Q
Microcytic Cells
A
- diameter less than 6um
- MCV less than 80 fL
- commonly associated with hypochromasia
- seen in IDA, hemiglobinopathies, inflammation, anisocytosis
- smaller than lymphocyte nucleus
10
Q
Anisocytosis
A
- mixture of normal, small, or large cells
- RDW will correspond, will be wide in histogram
11
Q
Poikilocytosis
A
- broad term for variation in shape and applied to many forms of RBC shapes (ex. spherocytes, sickle cells, schistocytes)
12
Q
Spherocytes
A
- lack central pallor, often microcytic
- commonly seen in hereditary spherocytosis, autoimmune hemolytic anemia, transfused cells, severe burns
- mcv would be low normal from loss of membrane
- know these four causes: fibrin strands, thermal injury, intrinsic abnormalities, immune hemolysis (ex.rheumatoid arthritis)
- mchc will be high (increased Hgb content for cell size) -> automatically perform pbs
- high mcv and mch -> cold agglutinin
- high mch and mchc -> lipemia
13
Q
Elliptocytes/Ovalocytes
A
- egg to slightly oval to sausage, rod, or pencil shape
- usually functionally normal
- seen in iron deficiencies, hemoglobinopathies (ex. thalassemia), hereditary elliptocytosis, megaloblastic anemias (B12, folate deficiency)
14
Q
Echinocytes/Burr Cells
A
- echinocyte: blunt, evenly spaced projections
- Burr cells: projections or spicules that are more uneven
- different from crenated cells which lack central pallor
- cause can be physiological environmental factors: increased pH , decreased albumin, metabolic state of cell, use of some chemicals,
- may be due to outer expansion of lipid bilayer compared to inner layer
- may be seen in severe renal disease, pyruvate kinase deficiency, burns, etc.
- occur in uremia, cancer of stomach, bleeding peptic ulcer, liver disease, heparin therapy, vit. E deficieny
15
Q
Acanthocytes
A
- have 2-20 uneven spicules or thornlike projections
- no central pallor
- caused by excess cholesterol with increased to phospholipid ratio resulting in increased area
- seen in liver disease, abetalipoproteinemia, post splenectomy, malabsorption, hypothyroidism, and vit E deficiency
16
Q
Stomatocytes
A
- slit-like pallor
- bowl shape in wet preparations
- seen in hereditary stomatocytosis, alcoholism, liver disease, Rh null phenotype, artifact
17
Q
Target Cell
A
- have central dark area of hemoglobin surrounded by colorless ring and peripheral ring of hemoglobin
- caused by excess cell membrane (increased cholesterol and phospholipid)
- associated with hemoglobinopathies, thalassemia, IDA, splenectomy, obstructive liver disease
- know these three causes*:
1. artifacts of air drying and Hgb precipt’n
2. decreased volume
3. increased surface membrane
18
Q
Schistocytes
A
- fragmented RBCs
- lack central pallor
- if central pallor present, report as non-specific poik
- 1-2 in field significant
- seen in microangiopathic anemias (lay down fibrin in blood vessels), heart valve hemolysis, severe burns, Heinz bodies, anemia, uremia
19
Q
Tear Drop Cells
A
- pulled beyond their range of deformability
- must be pointing in diff directions
- if in same direction, could be artifact from making smear
seen in myelofibrosis, myelophthisic anemia, thalassemias - form from liver and spleen getting larger -> smaller spaces
20
Q
Sickle Cells
A
- inherited disorder caused by a single amino acid substitution in the globin chain
- form in low O2 state
- present only in Hgb S inherited disorder
21
Q
Hgb CC Crystals
A
- hexagonal shape crystal with blunt ends and stain darkly
- caused by single amino acid substitution in globin chain
- get removed by spleen causing extravascular hemolytic condition
22
Q
Hgb SC Crystals
A
- caused when a patient inherits a Hgb S gene from one parent and Hgb C gene from another parent
- result is combination of two abnormal morphologies
- include finger-like projections or mitten-like appearance
23
Q
Howell-Jolly Bodies
A
- round, dark, purple bodies, usually appear singly
- are nuclear fragments composed of DNA
- impaired DNA synthesis such as megaloblastic anemia or splenectomy
- also seen in sickle cell anemia, congenital absence of spleen or hyposplenism
24
Q
Basophilic Stippling
A
- fine or coarse, evenly dispersed purple dots
- are composed of RNA
- caused by alteration of Hgb synthesis such as thalassemia
- found in megaloblastic, sideroblastic anemia, myelodysplasias, alcoholism
- seen in lead and arsenic poisoning
25
Q
Pappenheimer Bodies
A
- iron granules clustered at periphery of cell
- stains blue-purple with Wright’s and blue with Perl’s Prussian blue
- seen in post-splenectomy, megaloblastic, sideroblastic, hemolytic anemia, and thalassemia
26
Q
Siderocyte
A
non-nucleated mature RBC contained iron granules
27
Q
Sideroblast
A
nucleated RBC containing iron granules randomly dispersed
28
Q
Ringed sideroblast
A
5 or more granules covering at least 30% of the circumference of the RBC
29
Q
Cabot ring
A
- thin ring-like or figure 8 like structure inside RBCs
- may represent part of mitotic spindle, remnant of microtubules or filament of nuclear membrane
- seen in cases of impaired DNA synthesis
- seen in myelodysplastic syndromes, and megaloblastic anemia
30
Q
Heinz bodies
A
- composed of denatured globin attached to RBC membrane
- not visible with Wright’s b/c dissolved by methanol
- visible with supravital stains such as methylene blue, crystal violet, and brilliant cresyl blue
- caused by excess hydrogen peroxide in hexose monophosphate shunt pathway
- evidence is presence of bite cells where spleen removes part of RBC containing Heinz body
31
Q
Artifact
A
- can be caused by leaving stain too long or improper washing
- refractile
- use fine focus
- may resemble overlying platelets -> look for halo and should be in same plane
- stain ppt is amorphous and will not have same shape and morphology as bacteria
32
Q
Refractile RBCs
A
- result of improper drying or staining
- refractile morphologies are always artifacts
33
Q
Necrobiotic WBC
A
- result of nuclear degeneration and fragmentation (karyorrhexis) when WBC is dying
- ignore when performing WBC diff
