Haematology Definitions

Question 1

anisocytosis

Answer 1

Red cells show more variation in size than is normal.

Question 2

poikilocytosis

Answer 2

Red cells show more variation in shape than is normal.

Question 3

microcyte

Answer 3

RBC size < normal

Question 4

microcytic anaemia

Answer 4

Anaemia due to small RBCs

Question 5

microcytosis

Answer 5

Disorder characterized by presence of microcytes in the blood.

Question 6

macrocyte

Answer 6

RBC size > normal – can be round, oval or polychromatic

Question 7

macrocytic anaemia

Answer 7

Anaemia due to large RBCs

Question 8

macrocytosis

Answer 8

Disorder characterized by presence of macrocytes in the blood

Question 9

normochromic

Answer 9

Normal cell state

Question 10

normocytic

Answer 10

Red cells that are of normal size, or anaemia with normal sized RBCs

Question 11

hypochromia

Answer 11

Normal red cells ~ 1/3 of diameter is pale. This is a result of the disk shape of the red cell; the centre has less Hb so paler.

Hypochromia=cells have larger area of central pallor than normal as lower Hb content and concentration and a flatter cell=hypochromic

Hypochromia and microcytosis often go together.

Question 12

polychromasia

Answer 12

Increased blue tinge to cytoplasm of a red cell, indicating RBC is young.

Question 13

elliptocyte

Answer 13

RBC are elliptical in shape - occur in hereditary elliptocytosis and in iron deficiency

Question 14

spherocyte

Answer 14

Cells approximately spherical in shape.
Therefore have round, regular outline and lack central pallor.
Result from loss of cell membrane without loss of equivalent amount of Cytoplasm so cell forced to round up. No need to be 100% spherical.

Question 15

target cell

Answer 15

Accumulation of Hb in the centre of the area of pallor. Occur in obstructive jaundice, liver disease, haemoglobinopathies and hyposplenism.

Question 16

sickle cell

Answer 16

Result from polymerization of haemoglobin S when present in high concentration (sickle in shape)

Question 17

fragment

Answer 17

RBC broken up, aka schistocytes

Question 18

rouleaux

Answer 18

Stacks of RBCs, resembling a pile of coins. Results from alterations in plasma proteins

Question 19

agglutination

Answer 19

RBC agglutinates differ from rouleaux in that they are irregular clumps, rather than tidy stacks. Usually result from antibody on surface of the cells.

Question 20

Howell-Jolly body

Answer 20

nuclear remnant in a red cell, commonest cause is lack of splenic function

Question 21

leucocytosis

Answer 21

Too many WBCs

Question 22

leucopenia

Answer 22

Too few WBCs

Question 23

neutrophilia

Answer 23

Too many neutrophils

Question 24

neutropenia

Answer 24

Too few neutrophils

Question 25

lymphocytosis

Answer 25

Too many lymphocytes

Question 26

atypical lymphocyte

Answer 26

abnormal lymphocyte, mainly used in describing cells in infectious mononucleosis (‘glandular fever’)

Question 27

eosinophilia

Answer 27

Too many eosinophils

Question 28

monocytosis

Answer 28

Too many monocytes

Question 29

thrombocytosis

Answer 29

Too many platelets

Question 30

thrombocytopenia

Answer 30

Too few platelets

Question 31

toxic granulation

Answer 31

Heavy granulation of neutrophils, results from infection, inflammation and tissue necrosis (but is normal feature of pregnancy)

Question 32

left shift

Answer 32

Increase in non-segmented neutrophils/neutrophil precursors in the blood

Question 33

hypersegmented neutrophil

Answer 33

Increase in the average number of neutrophil lobes or segments, usually results from a lack of vitamin B12 or folic acid

Question 34

reticulocytosis

Answer 34

Increase in number of reticulocytes in the blood. Methylene blue dye binds to reticulum, indicating young RBCs.

Question 35

Irregularly Contracted Cell

Answer 35

IRCs irregular in outline but smaller than normal cells and have lost their central pallor. Usually result from oxidant damage to the cell membrane and Hb