Splenomegaly

Infections, eg, mononucleosis (Epstein-Barr virus), cytomegalovirus, acute HIV, endocarditis, histoplasmosis, malaria, schistosomiasis, leishmaniasis, filariasis
Chronic hemolytic anemia
Leukemia
Lymphoma
Extramedullary hematopoiesis, eg, myelofibrosis, marrow toxin
Polycythemia vera
Essential thrombocytosis
Cirrhosis or noncirrhotic portal hypertension
Congestive heart failure
Immune thrombocytopenias
Splenic vein thrombosis
Rheumatoid arthritis (Felty’s syndrome)
Systemic lupus erythematosus
Sarcoidosis
Wilson’s disease
Amyloidosis
Budd-Chiari syndrome
Gaucher disease
Niemann-Pick disease
Splenic cysts, hemangiomas, hamartomas, fibromas
Metastases, eg, melanoma
Eosinophilic granuloma (Langerhans cell histiocytosis, histiocytosis X)