5. Enlarged spleen

Question 1

What are the 3 broad categories of causes for splenomegaly

Answer 1

Congestion
Infiltration
Proliferation

Question 2

Congestion –> splenomegaly. explain? conditions?

Answer 2

Increased BP in splenic vein can cause congestion, hyperplasia and fibrosis of the spleen

This can be due to: direct congestion in splenic vein (splenic vein thrombosis) spontaneous or as a complication of pancreatitis OR anything that causes portal hypertension (cirrhosis or Right heart failure)

Cirrhosis : jaundice, varices, spider angiomas
Pancreatitis : severe epigastric pain radiating to the back - if spleen is enlarged → higher risk of thrombotic complications

Question 3

infiltration –> splenomegaly. explain?

Answer 3

Highly vascularised and plays a central role as a peripheral lymphatic organ
So is prone to infiltration by malignancies or depositary diseases
Malignancies: lymphoma, leukaemia, metastatic solid tumours
Depository: amyloidosis, sarcoidosis

Question 4

proliferation –> splenomegaly. explain?

Answer 4

The spleen is a lymphatic organ - blood borne pathogens → causes spleen to be hyperfunctioning
Viral : CMV, HIV, EBV
Bacterial: TB
Fungal: histoplasmosis
Parasitic: malaria

Filtering of abnormal cells and structures → hyperplasia
Spherocytosis
Haemaglobinopathies
Sickle cell disease

Extramedullary hematopoiesis
Myelofibrosis (a myeloproliferative disease)= haematopoiesis develops in the liver and spleen - massive splenomegaly