Anat Path - Spleen

Question 1

Define hypersplenism (1½)

Answer 1

Association between a peripheral blood pancytopaenia & splenic enlargement which may be 1o or 2o

Question 2

List seven (7) causes of splenomegaly (3½) (NB)

Answer 2

Congestion, Infection, Immune disorders, Red blood cell abnormalities, Neoplasms, Storage disorders, Amyloidosis

Question 3

Classify the causes of splenomegaly according to the size of the spleen and give two (3) examples of each (6) (Super NB)

Answer 3

• Grossly enlarged: Chronic myeloid leukaemia, Myelofibrosis, Chronic malaria, Gaucher’s disease, Kala-azar
• Moderately enlarged: Congestion, Amyloidosis, Haemolytic anaemia, Chronic lymphocytic leukaemia
• Mildly enlarged: Any of the above, Infection, Autoimmune disease, Felty’s disease

Question 4

List three (3) complications of splenomegaly (1½)

Answer 4

Anaemia, Thrombocytopaenia, Neutropaenia

Question 5

(2) List and explain three (3) distinct mechanisms of congestive splenomegaly (6)

Answer 5

• Pre-hepatic: Thrombosis of the extrahepatic portion of the portal vein or splenic vein
• Hepatic: Cirrhosis
• Post-hepatic: Raised pressure in the inferior vena cava
  o Transmitted to the spleen via the portal system
  o Usually associated with ascites and hepatomegaly
  o Usual causes- decompensated right heart failure and pulmonary or tricuspid disease

Question 6

Briefly describe the macroscopic and microscopic pathology of the spleen in congestive splenomegaly (6)/ Briefly describe the pathology of the spleen in this condition (3)

Answer 6

Variably enlarged spleen, may reach a massive size weighing a kg or more

Capsule  thickened and fibrotic

Cut surface
o Beefy-red colour with inconspicuous white pulp
o Contains scattered firm brown nodules
o Gamna Gandy bodies represent areas of healed infarction
o Composed of fibrous and elastic tissue with abundant haemosiderin and dystrophic calcification

Question 7

List two (2) examples of storage disorders that affect the spleen (1)

Answer 7

Gauchers disease (½), Niemann Pick disease (½), Mucopolysaccharidoses (½)

Question 8

Briefly explain the long-term effect of splenectomy on immunity (2)

Answer 8

Increased risk of infection by encapsulated organisms (1) (e.g. H. influenzae, K. pneumonia) due to defective opsonisation of organisms (1)

Question 9

Explain why haematogenous delivery of insoluble material into the spleen is common and give two (2) examples of the material that can go to the spleen (2)

Answer 9

20-25% of Q goes to spleen: blood delivery of insoluble material is frequent. Thrombi, tumour emboli, fat, foreign material

Question 10

Give two (2) examples of neoplasms that are known to spread to involve the spleen (1)

Answer 10

Lymphoma, leukaemia, melanoma

Question 11

Metastasis by tumour into the spleen is a relatively infrequent observation. Explain what allows the red pulp and white pulp to destroy metastases (2+2 = 4)

Answer 11

Red pulp: Inhospitable environment which tends to destroy sick cells e.g. old RBCs which have reduced cell membranes and are less pliable and able to traverse the circuitous sinusoids. Neoplastic cells which have nuclear abnormalities: less able to withstand traversing the circuitous sinusoids. Mechanical destruction in red pulp.

White pulp: Cell membranes of malignant cells are altered and seen as ‘nonself’so are destroyed immunologically. Immunological destruction in white pulp.