The Spleen, WBCs, Cytopenia

Question 1

Describe the role of the spleen

Answer 1

Secondary reserve of blood,
sequestrian, phagocytosis,
extrameduallary haemopoiesis,
immunological function (T, B cells)

Question 2

What are the causes for splenomegaly

Answer 2

most commonly malaria = spleen over working (immune response/RBC removal – anaemic).

Cancer = infiltration of abnormal cells (e.g. CLL – expansion of white cell nodules).

Granulomas present (sarcoidosis, TB).

Back pressure = portal hypertension.

Question 3

Outline palpating the spleen

Answer 3

Should never be able to palpate.

Start at the RIF (right iliac fossa), feel for spleen edge, move towards your hand on inspiration, feel splenic notch, measure in cm

Question 4

What is hypersplenism?

Answer 4

Dilutional effect = blood in the spleen for a longer amount of time = pancytopenia or thrombocytopenia

Question 5

What is the clinical significance of splenomegaly

Answer 5

Compressed stomach,
rupture (very dangerous),
trauma = haematoma around spleen,
infarction of infarct spleen tissue due to small capillary damage ~ asplenic

Question 6

What is the clinical significance of hyposplenism

Answer 6

Lack of functioning splenic tissue

Cause = splenectomy, sickle cell disease (infarcts then fibrosis), coeliac disease.

VERY high risk of sepsis

Question 7

What 3 MO are important to vaccine against in a patient who is hyposplenic?

Answer 7

Pneumococcus,

Haemophilus influenzae,

Meningococcus

Question 8

Describe the common causes of leucocytosis

Answer 8

Increase in WBCs = infection

Question 9

Outline the common causes of leucopenia

Answer 9

Low WBC count = acute viral infect, chemo, radiation, aplastic anaemia

Question 10

What does multi lobes neutrophils signify?

Answer 10

B12 def

Question 11

Describe the common causes and clinical significance of neutropenia

Answer 11

Low neutrophil count

immune destruction, 
viral infection, 
sepsis, 
splenic pooling, 
reduced prod (B12/folate def, cancer, aplastic anaemia, radiation, drugs)

Question 12

What is the most common cause of neutropenia by reduced prod?

Answer 12

Viral infection

Question 13

What are the clinical consequences of neutropenia?

Answer 13

Severe life threatening bacterial infect, fungal infection, mucosal ulceration

Question 14

What are the causes of neutrophilia?

Answer 14

High neutrophil count = bact infection, tissue damage, cancer, steroids, acute haemorrhage, myoproliferative disease, high G-CSF (cytokine), smoking

Question 15

Describe lymphocytosis

Answer 15

High lymphocyte count = viral infect, bacterial infect, stress, post splenectomy, smoking, CLL, lymphoma (cell spill out of infiltrated bone marrow)

Question 16

Outline eosinophilia

Answer 16

Increased eosinophils = allergy, drugs, parasites, leukaemia

Question 17

What is pancytopenia?

Answer 17

Lowering of all cells = reduced prod (B12/folate def, malignancy, marrow fibrosis, aplastic anaemia, radiation, drugs, viruses) OR increased removal (haemophagocytosis)

Question 18

Outline the differential diagnosis in a patient with a raised haemoglobin concentration

Answer 18

Smoking, 
live at higher altitudes, 
poor lung function, 
EPO doping, 
increased RBC prod

Question 19

What are the clinical/lab features that help distinguish polycythaemia vera from other causes of a high [Hb]?

Answer 19

= neoplasm of bone marrow

high RBCs/WBCs/platelets. 
Low EPO. 
Itching (abnormal histamine release), 
red/blue skin, 
headaches, 
erthromelalgia = peripheral pain by increased platelets/tiny clots

Question 20

In a centrifuged blood sample where would you find the highest conc of neutrophils?

Answer 20

Buffy coat

Question 21

How many femtolitres are in a L?

Answer 21

10^15

Question 22

Which artery supplies the spleen?

Answer 22

Splenic artery

Question 23

What would the presence of Howell-Jolly bodies indicate?

Answer 23

A damaged spleen

These cell contain DNA remains which have normally been expelled = damaged spleen not removing abnormal RBCs