Splenomegaly

Splenomegaly is an enlargement of the spleen over it's normal size. The size of the spleen can be variable: normal adult spleen is about 10-13 cm long and 6-8 cm wide.

Classification
Hypersplenism is defined as an increased activity of the spleen which can lead to the splenomegaly. Complications of having splenomegaly is a ruptured spleen which is often an indication for splenectomy, in this case the spleen's function is taken over by the liver and the bone marrow.
 * Adult classification:
 * 1) mild splenomegaly – weight of the spleen is up to 500 g, examples: acute bacterial infection, chronic venous stasis, infectious mononucleosis
 * 2) moderate splenomegaly – weight of the spleen is between 500 and 1000 g, examples: steatosis, amyloidosis, chronic bacterial infections, autoimmune hemolytic anemia
 * 3) severe splenomegaly – weight of the spleen is over 1000 g, examples: hemolytic anemia, primary tumors of the spleen, chronic myeloid leukemia.

Causes
The main causes of the splenomegaly are :
 * infection : in children it can be caused by any types of infectious illnesses (reaction to an antigenic stimulus)
 * bacterial infections
 * mainly EBV and CMV infections
 * parasite infections, for example malaria, leishmaniasis
 * cardiovascular diseases :
 * right-sided heart failure,
 * thrombosis of the portal vein system and a. lienalis (for example due to the pancreatic cancer) ,
 * endocarditis
 * portal hypertension (in adulthood commonly due to the liver cirrhosis );
 * hemolysis and increased elimination of the erythrocytes:
 * Intracorpuscular hemolytic anemia: early thalassemia, spherocytosis, sickle cell anemia
 * Extracorpuscular hemolytic anemia
 * Tumors:
 * myeloproliferative disorders: chronic myeloid leukemia, extramedullary hematopoiesis due to the primary myelofibrosis,
 * lymphoproliferative disorders: hairy cells leukemia, splenic lymphoma
 * metastasis to the spleen
 * autoimmune diseases :
 * rheumatoid arthritis,
 * systemic lupus erythematosus
 * amyloidosis
 * storage disorders, mainly lysosomal : mucopolysaccharidosis type I, II and VII; Gaucher disease, Niemann-Pick disease, generalized gangliosidosis, Wolman's disease