MEH - The Spleen

Question 1

What is ‘red pulp’ in the spleen?

Answer 1

Sinuses lined by endothelial macrophages and cords. Red cells pass through this preferentially

Question 2

What is ‘white pulp’ in the spleen?

Answer 2

Similar structure to lymphoid follicles. White cells pass through this preferentially

Question 3

Does an enlarged spleen cause pain in most cases?

Answer 3

No, it usually causes a feeling of fullness

Question 4

What are the functions of the spleen in adults?

Answer 4

• sequestration and phagocytosis (old/abnormal red cells removed by macrophages)
• blood pooling (platelets and red cells can be rapidly mobilised during bleeding)
• extramedullary haemopoiesis (pluripotential stem cells proliferate during haematological stress/if bone marrow fails)
• immunological function

Question 5

How should splenomegaly be palpated?

Answer 5

Start to palpate in right iliac fossa and feel the edge of the spleen move towards your hand on inspiration. Feel for splenic notch and measure in cm from costal margin in mid-clavicular line

Question 6

Give some reasons for splenomegaly

Answer 6

• back pressure, eg due to portal hypertension in liver disease
• overworking red/white pulp
• extramedullary haemopoiesis
• expanding as infiltrated by foreign material/cells eg cancers, sarcoidosis

Question 7

What are the three categories of splenomegaly?

Answer 7

Massive, moderate and mild

Question 8

What is hyposplenism?

Answer 8

Lack of functioning splenic tissue - may be due to splenectomy, sickle cell disease, coeliac disease.

Question 9

What is a risk of hyposplenism?

Answer 9

Patients are at risk of overwhelming sepsis, particularly from encapsulated organisms, eg. Pneumococcus

Question 10

What are Howell Jolly bodies?

Answer 10

DNA remnants seen inside cells on a blood film which appear as dark spots. They suggest that the spleen has been removed.

Question 11

What is cytopenia?

Answer 11

Umbrella term for a reduction in the number of blood cells.

Question 12

What is the difference between anaemia and erythrocytosis?

Answer 12

Anaemia = low red cell count
Erythrocytosis = high red cell count

Question 13

What is the difference between leucopenia and leucocytosis?

Answer 13

Leucopenia = low white blood cells
Leucocytosis = high white blood cells

Question 14

What is the difference between neutropenia and neutrophilia?

Answer 14

Neutropenia = low neutrophil count 
Neutrophilia = high neutrophil count

Question 15

What is the term for a high lymphocyte count?

Answer 15

Lymphocytosis

Question 16

What is pancytopenia?

Answer 16

Low red blood cells, white blood cells and platelets

Question 17

What is the difference between thrombocytopenia and thrombocytosis?

Answer 17

Thrombocytopenia = low platelet count
Thrombocytosis = high platelet count

Question 18

How do neutrophils appear on a slide?

Answer 18

Stain pink, have 3-5 segments

Question 19

What does the hormone G-CSF do?

Answer 19

• increases production of neutrophils
• decreases time to release of mature cells from bone marrow
• enhances chemotaxis
• enhances phagocytosis and killing of pathogens

Question 20

How long do neutrophils live for?

Answer 20

1-4 days

Question 21

Why might recombinant G-CSF be injected post-chemotherapy?

Answer 21

Increases amount of neutrophils, so can reduce neutropenic infections

Question 22

Give some examples of things which may cause neutropenia

Answer 22

• B12/folate deficiency
• infiltration of bone marrow by malignancy/fibrosis
• aplastic anaemia
• radiation
• drugs (chemotherapy, antibiotics, anti-epileptics etc.)
• viral infection
• congenital disorders

Question 23

What are the roles of monocytes?

Answer 23

• respond to inflammation and antigenic stimuli

- migrate to tissues where they become macrophages and phagocytose pathogens

Question 24

What is contained within lysosomes in monocytes?

Answer 24

Lysozyme, complement, interleukins, arachidonic acid, CSF

Question 25

What may cause monocytosis?

Answer 25

Chronic inflammatory conditions, chronic infection, carcinoma, leukemias

Question 26

How long do eosinophils live for?

Answer 26

8-12 days, of which 3-8 hours are spent in the circulation

Question 27

What are the roles of eosinophils?

Answer 27

• deal with some parasites
• mediator of allergic response
• migrate to epithelial surfaces
• phagocytosis of antigen-antibody complexes
• mediate hypersensitivity reactions

Question 28

What is contained in the granules of eosinophils?

Answer 28

Arginine, phospholipid, enzymes

Question 29

How do eosinophils appear histologically?

Answer 29

Stain pink with two purple central segments

Question 30

What can cause eosinophilia?

Answer 30

• allergic diseases, eg. asthma
• drug hypersensitivity
• Chung-Strauss
• parasitic infection
• skin diseases
• leukaemia/lymphoma

Question 31

How do basophils appear histologically?

Answer 31

Stain purple, look a bit like blackberries. They are the largest immune cell

Question 32

When are basophils active?

Answer 32

In allergic reactions and inflammatory conditions

Question 33

What is contained within the granules of basophils?

Answer 33

Histamine, heparin, hyaluronic acid, serotonin

Question 34

How do lymphocytes appear histologically?

Answer 34

Stain pink with a large pink/purple centre

Question 35

Give some reactive causes of lymphocytosis

Answer 35

• viral infections
• bacterial infections
• stress related (MI/cardiac arrest)
• post-splenectomy
• smoking

Question 36

Pnacytopenia can result due to increased removal of blood cells. Give some reasons for increased removal

Answer 36

Immune destruction, splenic pooling, haemophagocytosis

Question 37

What is aplastic anaemia?

Answer 37

Pancytopenia with a hypocellular bone marrow in the absence of an abnormal infiltrate and with no increase in reticulin

Question 38

What would be the symptoms of pancytopenia?

Answer 38

Symptoms of anaemia + symptoms of thrombocytopenia + symptoms of neutropenia + symptoms of underlying cause