Comprehensive Review: Extramedullary Hematopoiesis in Patients with Beta Thalassemia Major (transfusion dependent thalassemia)

Abstract Introduction: Thalassemia is one of the most common hemoglobinopathies, with around 5% of world's population expected to have some degree and type of thalassemia. Beta thalassemia (BT) occurs due to a deficient production of the beta-globin chain of hemoglobin. BT is classified into minor, intermedia, and major, defined by their clinical and laboratory findings. Extramedullary hematopoiesis is one of the complications of BT, primarily seen in minor/intermedia subtypes. EMH is the production of blood cells outside the marrow as a compensatory response to longstanding hypoxia. Due to chronic transfusions, it is not expected in patients with beta thalassemia major (BTM). However, there are multiple case reports of EMH in BTM. The incidence of EMH in BTM is thought to be