INTRODUCTION
Beta thalassemia major is the severe form of beta thalassemia, which is caused by mutations in beta globin gene, either reduced (β+) or absent (β0) in hemoglobin A resulting in unbound α globin chains that accumulate in erythroid precursors in the bone marrow and in the mature erythrocytes leading to ineffective erythropoiesis and peripheral hemolysis. About 1.5 % of the world population are carriers of β thalassemia [1].
In severe disease, extramedullary hematopoiesis (EMH) -which is production of blood elements outside the bone marrow- occurs mostly in the liver and the spleen but in rare cases can manifest as bony masses that behave clinically like tumors, leading to optic nerve atrophy, spinal cord compression and other clinical scenarios [2,3].
Here we present a case of a 31-year old Pakistani woman with transfusion-dependent beta thalassemia (TDBT), who complained of low back pain due to a mass reflecting extra medullary hematopoiesis which very rarely occurs in the sacrum as there was only one case reported in the literature and this is the second one.