Hematopoesis & Blood Cell Morphology Flashcards
What are the two main compartments involved in hematopoesis?
- Myeloid
- bone marrow & derived cells
- Lymphoid
- thymus, lymph nodes, spleen
How do we not run out of stem cells?
pluripotent hematopoietic stem cells self-renew
Cells from the “blast” stage and above express what marker?
This includes what types of cells?
CD34- stem-cell marker
hematopoietic stem cells
multilineage (multipotent) progenitor cells
progenitor cells
Where does hematopoiesis take place from 0-2 months gestation?
yolk sac
Where does hematopoiesis take place from 2-7 months gestation?
liver, spleen
Where does hematopoiesis take place from 5-9 months gestation?
bone marrow
How does the portion of marrow capable of hematopoiesis change as we age?
- Infancy & childhood: all marrow is hematopoietic
- Puberty & adulthood: restricted to central skeleton & proximal ends of femurs and humeri
- Normal cellularity is ~ (100-age) +/- 20%
What cells are involved in hematopoiesis & what does each cell type give rise to?
- Hematopoietic stem cells
- self-renewal
- produce multi-lineage progeny
- Multi-lineage (multipotent) progenitor cells
- single or limited lineage progenitor cells
- Progenitor cells
- irreversible lineage commitment
What is true about hematopoietic stem cells, multi-lineage progenitor cells & progenitor cells?
morphologically unrecognizable & express CD34
What is the first recognizable cell in lineage?
They have what specifics of lineage?
blast cell
mitotically active / variable expression CD34
immunophenotype or cytochemistry of lineage
After blasts cells, cells have what specifics of lineage?
immunophenotype & cytochemistry of lineage
What morphologic changes are associated with granulopoiesis?
- cells & nuclei become smaller
- nucleoli disappear
- primary granules disappear
- secondary granules appear
- chromatin becomes more condensed
- nuclei become segmented
Identify the cell stage of granulopoiesis shown in the provided images.
- blast: not much in the way of granularity, multiple nucleoli
- promyelocyte: pretty good size cell, with a lot of dark blue/purple granules, immature looking nuclear chromatin, can see nucleolus
- metamyelocyte: nucleus starts to indent, when secondary granules start to appear & will see “dawn of neutrophilia” the zone of lighter color near adjacent to the nucleus (golgi)
- band: nucleus is indented more than 50% of diameter but no nuclear lobes
How do you differentiate a neutrophilic band from a mature neutrophil?
- neutrophilic band
- non-segmented nucleus
- granules are small, evenly distributed, and stain pink or pink and blue
- mature neutophil
- nucleus separated into distinct lobes connected by narrow filament
- granules evenly distributed, light pink or pink-blue
Identify the mature leukocytes shown in the provided images
What is the largest of the peripheral blood leukocytes?
monocyte
What type of cell is shown in the provided images?
normal lymphocytes
- small to large
- variable mounts of pale blue/pink to dark blue cytoplasm
- but do NOT have indented nucleus
- +/- fine pink cytoplasmic granules
What type of cell is shown in the provided images?
normal lymphocytes
- small to large
- variable mounts of pale blue/pink to dark blue cytoplasm
- but do NOT have indented nucleus
- +/- fine pink cytoplasmic granules
What is the name of the precursor shown in the provided image?Erythroid Island
What is the name of the precursor shown in the provided image?
Identify the early, intermediate & late erythroblasts in this bone marrow aspirate.
chromatin will become more coarse & dense as the cells mature
nuclei remain round/oval & the cytoplasm becomes more orange
What type of cell is shown in the provided images?
Normal Erythrocytes
“central zone of pallor”
Why is the biconcave disc an idea shape for red blood cells?
can carry plenty of hemoglobin
makes them very deformable but not fragile
Megakaryocytes have what type of genetic material?
polyploid
How do megakaryeocytes mature?
by a series of nuclear replications with a common cytoplasm, leading to multi-lobed, polyploid nuclei
What process is shown in the provided image?
megakaryopoiesis
What are the indications for receiving a bone marrow biopsy & aspiration?
- Diagnosis / follow-up of hematolymphoid neoplasms
- staging of lymphomas, some solid tumors
- investigation of unexplained blood abnormality
- fever of unknown origin, suspected bone marrow infection
- unexplained radiographic findigns
- pre-transplantation work up
What are the contraindications for receiving a bone marrow biopsy & aspiration?
not meeting the criteria of having one done
What is the most common site for bone marrow aspiration & biopsy?
posterior iliac crests
What is a bone marrow biopsy used for?
biopsy of trabecular bone
- to determine architectural relationships
- cellularity
- myeloid:erythroid estimation
- cell distribution
- fibrosis and other marrow infiltrating processes
- bony and vascular abnormalities
Bone marrow aspirate is better when looking at what feature as compared to a bone marrow biopsy?
cytological details
growing cultures
What structure is shown in the provided images?
core biopsy from the patient & on the slide
What are two procedures commonly preformed on the core biopsy?
What are bone marrow aspirates most commonly used for?
cell counts
cytologic evaluations
special studies
What are two special features that are performed on the bone marrow aspirate?
What substances in shown in the provided image?
bone marrow
When looking at a peripheral slide, what RBC abnormalities are you looking out for?
size
shape
inclusions
miscellaneous
What is the normal size of a RBC?
7-8 microns in diameter
What characteristics determine a small RBC? What is its name?
< 80 fL and pale
zone of central pallor is > ⅓ the diameter of the cell
microcyte
Microcytes are seen in what conditions?
- iron deficiency
- chronic disease
- sideroblastic anemia
- heavy metal poisoning
- thalassemia
What condition is shown in the provided image?
MIcrocytic Hypochromic
- pale / small RBC
- larger “area of central pallor”
What characteristics determine a small RBC? What is its name?
>100 fL, ell hemoglobanized RBC
often oval in shape
Macrocytes
Macrocytes are seen in what conditions?
- vitamin B12 deficiency
- folate deficiency
- medication / toxin effect
- myeloid neoplasms
What condition is shown in the provided image?
Macrocytic erythrocytes
What defect leads to microcytic cells? What does this mean for hemoglobin content?
cytoplasmic defect - small amounts of hemoglobin
What defect leads to macrocytic erythrocytes? What does this mean for hemoglobin content?
nuclear defect - normal amount of hemoglobin
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Spherocytes
cells are spherical & lose bioconcave disk shape– due to loss of membrane w/o loss of cytosol
What aspect of spherocytes makes them pathological?
much less deformable
Spherocytes are seen in what pathologies?
immune hemolytic anemia
hereditary spherocytosis
burns
transfusion
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Elliptocytosis / ovalocytosis
abnormalities of cytoskeletal proteins
Elliptocytosis / ovalocytosis is seen in what conditions?
Hereditary forms
acquired forms:
thalassemia
iron deficiency
myelofibrosis
myelodysplasia
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Target Cell -
redundant membrane in relation to the volume of the cell
What aspect of target cells makes them pathological?
too floppy, which makes them too fragile
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Acanthocytes
irregularly sized & irregularly distributed pointed projections from the cell surface
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
echinocytes
short, numerous projections all around the cell, fairly even in size
How are the spicules seen in acanthocytes different from those seen in echinocytes?
- Acanthocytes
- unevenly distributed over RBC surface
- unequal length
- Echinocytes
- evenly distributed over RBC surface
- short, blunt
Acanthocytes are seen in what pathological states?
- liver disease
- myelodysplastic neoplasms
- malnutrition
- abetalipoproteinia
Echinocytes are seen in what pathological states?
- liver or renal disease
- shortage artifact
- inherited enzyme deficiency
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Stomatocytes
cup-shaped
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Stomatocytes
cup-shaped
Stomatocytes are most commonly seen in what condition?
alcohol abuse syndromes
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Schistocyte
red cell fragments - RBC basically get clothes-lined on a fibrin strand or a strandform of platelet aggregates
Schistocytes can be commonly mistaken for what other misshapen RBC? What is the differentiating factor?
Sickle Cells – NOT cell fragments
schistocytes ARE fragments
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Sickle-cells
point mutation on beta chain of hemoglobin
sickle in conditions of hypoxia / dehydration
What condition is depicted by the provided blood smear? What types of RBC deformations are seen in the slide?
Hemoglobin C Disease
What is the name for the type of cell depicted by the black arrow? They are seen in what condition?
Bit Cell (Degmacyte)
or G6PD deficiency
How are “bite cells” formed?
When denatured hemoglobin aggregates (Heinz bodies) are removed from RBC by the spleen
What type of RBC shape abnormality is shown in the provided image? Underlying cause?
Teardrop Cells (Dacrocytes)
due to mechanical distortion of the cell
Teardrop Cells are most commonly seen in what conditions?
- primary (idiopathic myelofibrosis)
- secondary (reaction to myeloma, solid tumors, therapy)
Teardrop Cells are most commonly seen in what conditions?
- primary (idiopathic myelofibrosis)
- secondary (reaction to myeloma, solid tumors, therapy)
What type of pathological RBC condition is shown in the provided image?
Polychromasia
- blue-gray color of immature RBCs due to residual cytopplasmic ribosomal material
- immature RBCs are larger than mature RBCs
Polychromasia is most commonly seen in what conditions?
reticulocytosis - hemolytic anemias & regenerating marrow
What is reticulocytosis?
premature release of immature cells from marrow in times of increased RBC turnover
What is the name of the cells with the dark blue inclusions?
Reticulocytes (blue = RNA aggregates)
What type of RBC inclusion is shown on the provided slide? What are they?
Howell-Jolly Bodies
small nuclear remnant, typically single & round
Howell-Jolly Bodies are commonly seen in what conditions?
post-splenectomy states
hemolytic anemias
megaloblastic ane
What type of RBC inclusion is shown on the provided slide? What are they?
Pappenheimer Bodies / Granules
iron-containing mitochondrial remnants
occur in small clusters near periphery of cell
Pappenheimer Bodies/Granules are most commonly associated with what pathology?
seen in sideroblastic anemia & post-splenectomy states
What type of RBC inclusion is shown on the provided slide? What are they?
Basophilic stippling
RNA, aggregates of ribosomes
What are the usual causes of coarse basophilic stippling?
lead intoxication
thalassemia
What are the usual causes of fine basophilic stippling?
many anemias
What pathology is shown in the provided image?
cold agglutinins
immune-mediated agglutintion
What pathology is shown in the provided image?
Rouleaux
NOT immune-mediated
caused by high protein level that messes with negative charges on the surface of RBC
