Extramedullary hematopoiesis (EMH) is a compensatory reaction caused by the presence of hematopoietic precursors outside the bone marrow, ineffective erythropoiesis and patients with chronic hemolytic anemia. The most frequent cause of EMH is thalassemia intermedia, that produces an increase in demand of the hematopoietic system caused by anemia and is not reduced by transfusion therapy.