Defective globin chains lead to excessive haemolysis and compensatory haematopoiesis within bone marrow, which in turn leads to enlargement of the medullary cavities and thinning of cortices.
The liver, spleen, kidney, posterior mediastinum and lymph nodes are the most common sites of extramedullary haematopoiesis.
On plain chest radiography, thoracic extramedullary haematopoiesis lesions appear as smooth or lobulated posterior mediastinal masses.
On non-contrast computed tomography (CT) scanning, extramedullary haematopoiesis lesions appear as soft tissue masses that are denser than fat.
3) However, mixture of blood products of different age within the extramedullary haematopoiesis foci results in increased or decreased T1 or T2 signal.
Bone marrow is the site of haematopoiesis in adults.
Together, these observations strongly suggest that osteogenesis and haematopoiesis are functionally linked.
An essential prerequisite for the development of normal haematopoiesis in the bone marrow is endochondral ossification (90-92) which provides a crucial interrelationship between ossification and maturation of haematopoietic processes in mammals.