Splenomegaly and hypersplenism
- Lesion
A spleen grows when it works harder, holds back blood, is invaded by cells or stores material. A big spleen can trap blood cells.
What it is
The spleen filters blood, removes old and damaged cells, mounts immune responses and can make blood cells when the marrow fails. It enlarges through five mechanisms: infection and immune activation, congestion from portal hypertension or heart failure, haematologic neoplasms and extramedullary haematopoiesis, increased removal of abnormal red cells, and storage or infiltrative diseases. A large spleen of any cause can sequester and destroy blood cells, lowering counts (hypersplenism).
Structure
- Acute splenitis: soft, diffluent red pulp full of neutrophils and plasma cells; sometimes abscesses.
- Chronic congestion: firm, enlarged spleen with dilated sinusoids, thick fibrotic cords and Gamna–Gandy bodies.
- Infiltrative: white pulp expansion in lymphomas, red pulp in hairy cell leukaemia and myeloid neoplasms, pale foamy cells in storage disorders.
Step by step
- Increased work: immune stimulation enlarges the white pulp; removal of abnormal red cells enlarges the red pulp.
- Raised venous pressure (portal hypertension, right heart failure, splenic vein thrombosis) dilates sinusoids.
- Neoplastic or extramedullary haematopoietic cells, or storage macrophages, fill the organ.
- Slow transit through the cords exposes blood cells longer to macrophages.
- Cells are pooled and destroyed: anaemia, neutropenia and thrombocytopenia (hypersplenism).
Splenomegaly by mechanism
| Mechanism | Examples | Size |
|---|---|---|
| Infection and immune activation | Endocarditis, mononucleosis, tuberculosis, typhoid, brucellosis, malaria, leishmaniasis, lupus | Mild to massive (malaria, leishmaniasis) |
| Congestion | Cirrhosis, portal or splenic vein thrombosis, right heart failure, schistosomiasis | Moderate to massive |
| Haematologic neoplasm and extramedullary haematopoiesis | CML, myelofibrosis, hairy cell leukaemia, lymphomas | Often massive |
| Red cell destruction | Hereditary spherocytosis, thalassaemia, autoimmune haemolysis | Moderate |
| Storage and infiltration | Gaucher and Niemann–Pick disease, amyloidosis, Langerhans cell histiocytosis | Moderate to massive |
| Mass lesions | Cysts, haemangioma, metastases | Variable |
Clinical notes
- A dragging feeling in the left upper quadrant, early satiety, and cytopenias.
- In Colombia, chronic malaria and visceral leishmaniasis (Caribbean region) are important causes of a very large spleen in endemic zones.
- A rapidly enlarging soft spleen is at risk of rupture.
Test yourself
Think of the answer, then tap the question to see it.
What is the main cause of congestive splenomegaly?
Cirrhosis with portal hypertension.
What are Gamna–Gandy bodies?
Fibrotic nodules encrusted with iron and calcium from old haemorrhages in a chronically congested spleen.
What are three causes of massive splenomegaly?
Chronic myeloid leukaemia, primary myelofibrosis and chronic malaria (also hairy cell leukaemia, visceral leishmaniasis, Gaucher disease).
Elsewhere in DurgiPedia
- Lymph node and spleen under the microscope
- Spleen: white pulp, red pulp, asplenia
- The red cell life cycle and the spleen
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Splenomegaly: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Malaria in Brazil, Colombia, Peru and Venezuela: current challenges in malaria control and elimination (Malaria journal, 2017).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.