Splenomegaly: Causes and Mechanisms

Key points

• • The spleen filters old red cells, mounts immune responses and can restart blood formation, so disease in any of these roles can enlarge it.
• • Congestive splenomegaly comes from raised pressure in the portal or splenic vein, most often from cirrhosis.
• • An increased functional workload can enlarge the spleen when it is busy destroying abnormal cells, as in haemolytic anaemias and infections such as malaria and infectious mononucleosis.
• • Infiltrative causes include blood cancers such as leukaemia and lymphoma, and storage diseases such as Gaucher disease.
• • Among the classic causes of a massive spleen are chronic myeloid leukaemia, myelofibrosis, chronic malaria and visceral leishmaniasis, though it is not limited to these.
• • An overactive enlarged spleen can trap and destroy too many blood cells, causing hypersplenism with low counts.