POIKILOCYTOSIS prt. 2 Flashcards
The hallmark of hemolytic anemia secondary to red cell fragmentation is the_______, which takes several forms.
schistocyte
When a red cell attempts to pass between fibrin strands, altered vessels, or damaged heart valve prostheses, it may be cleaved and fragmented and become a_______
The erythrocyte trying to squeeze through an opening half its diameter becomes stretched and develops a blister because of the shear stress of the flowing blood.
When this cell passes through the spleen, it is fragmented into two pieces, and the membrane is less deformable. Fragmented red cells do not survive long in the circulation.
schistocyte
Schistocytes (Greek word schistos, “_____”) or schizocytes (Greek schizo, “_____”’) result from membrane damage; they are not hereditary.
cloven
split
Schistocytes include helmet, triangular, and a variety of small, irregular shapes with a few pointed extremities.
The finding of_____ and _____ is strongly suggestive of a microangio-pathic hemolytic anemia or traumatic hemolytic anemia
helmet and fragmented cells
occur in patients with severe burns, renal graft rejection, glomerulonephritis, vasculitis, thrombotic thrombocytopenic purpura, and diffuse intravascular coagulation
Schistocytes
accompanying march hemoglobinuria most likely are attributable to mechanical damage to the cells in the feet of individuals on long walking expeditions.
Schistocytes
schistocyte with one or more hornlike projections has been identified as a______ (Greek_______, “horn”)
keratocyte
keras
These cells may or may not have a normal volume and usually no area of central pallor.
A________ is the result of an erythrocyte being caught on a fibrin strand, which could cut the cell in two.
As the sides of the erythro cyte are pushed against the fibrin strand, they tend to fuse together.
When this cell escapes from the fibrin strand, it may have a vacuole-like area in the fused portion (this is known as a blister cell).
This vacuole ruptures to form the_______
— a damaged red cell with horns.
keratocyte
do not remain in circulation for more than a few hours, as they are fragile
They are a rare and interesting phenomenon.
Some morphologists report helmet cells, which actually look like a helmet, as ______
Keratocytes
pear shaped with a blunt pointed projection and
may be normal size, small, or large; “teardrops”
dacryocytes
have been so labeled because of their shape (Greek dakry, “tear”)
Dacryocytes (teardrops)
They may also be pear shaped with a blunt pointed projection and may be normal size, small, or large.
Dacryocytes (teardrops)
If a red cell contains a rigid inclusion, such as a Heinz body, the portion with the inclusion cannot pass through small openings of splenic sinuses and thus remains behind.
As the red cell squeezes through the small opening, it is stretched beyond its ability to regain its original shape.
Thus, a teardrop or pear shape is created.
Dacryocytes
typically are observed in myelofibrosis with myeloid metaplasia because of the large size of the spleen.
Other conditions with ______ include myelophthisic anemia, pernicious anemia, B-thalas-semia, drug-induced Heinz body formation, tuberculosis, and tumor metastasized to the marrow.
Teardrop cells
Dacrocytes
Red cells containing ___________________ squeeze through the splenic sinuses, hence will have its original shape STRETCHED (causing teardrop-shaped cells)
Heinz bodies
occur in severe burns as
small, round cells that may be smaller than platelets; they
are the result of thermal damage to the cell membrane.
Microspherocytes
Another name for microspherocytes
microspherules
Microspherocytes in rare hereditary HA occur at what temperature?
45 degrees C
Normocytes (normal RBCs) fragment at what temperature?
49 degrees C
T or F: MCV of those with rare hereditary HA designated pyropoikilocytosis have EXTREMELY LOW MCV
T
a large, pale-pink staining ghost of a red cell—the membrane
remaining after the contents have been released; as large as leukocytes
Semilunarbodies
Other names for semilunar bodies
half-moon cell/crescent cell
T or F: Semilunar bodies are ALWAYS acquired
T
Semilunar bodies are frequently seen in: (conditions)
Malaria & conditions causing overt hemolysis
Three types of poikilocytes characteristic of three abnormal hemoglobins (abnormal hemoglobin content)
- drepanocytes (from Hb S)
- Hb CC crystals
- Hb SC crystals
Three types of poikilocytes characteristic of three abnormal hemoglobins (abnormal hemoglobin content)
- drepanocytes (from Hb S)
- Hb CC crystals
- Hb SC crystals
cells that have been changed from the normal disc shape by the long
rod-shaped polymers of the inherited abnormal Hb S
Drepanocytes
Drepanocytes are also known as
sickle cells
A red cell does not appear sickled until it has lost its _________
and has been fully _____________.
nucleus; hemoglobinized
___________ are thin
and elongated with pointed ends and are well filled with
Hb. They may be curved or straight or have S, V, or L shapes.
Sickle cells/drepanocytes
T or F: The change in shape of drepanocytes is striking and IRREVERSIBLE secondary to permanent membrane damage by the polymerization of Hb S
T
Typical sickle cells are observed in films from patients with ______________ Hb S disease (Hb SS) but are not often
seen in ___________ Hb S (Hb AS; sickle trait) except under unusual situations when there is low in vivo oxygen tension.
homozygous; heterozygous
Meaning of drepanos
sickle
2 poikilocytes associated with malaria
1) semilunar bodies (poikilocyte secondary to trauma)
2) drepanocytes (poikilocyte secondary to abnormal Hgb content)
Drepanocytes are caused by a ________ mutation on the 6th position of amino acids (glutamic acid is changed to ________)
point (mutation); valine
intracellular crystals that are hexagonal with blunt ends and are darkly stained; these angular crystals form within the cell membrane when Hb C crystallizes
Hemoglobin CC crystals
T or F: Frequently, the cell membrane is not visible, and the crystal appears to be free (Hgb CC crystals). At times, several smaller CC crystals form within the red cell.
T
