Serial Imaging and Burnout Transition of Extramedullary Hematopoiesis in Sickle Beta-thalassemia: A Two-year Case...

The synthesis of blood cells, initiated during fetal development, transitions from the yolk sac to the liver and spleen, and finally to the bone marrow by 18 weeks of gestation, continuing throughout adulthood. Postnatally, hematopoiesis occurs exclusively in the bone marrow, but can be taken over by other organs in various hematological disorders. Extramedullary hematopoiesis (EMH) can involve numerous organs and lead to conditions such as hepatomegaly, splenomegaly, and paraspinal masses. Rarely, EMH occurs in atypical sites such as the gastrointestinal tract, lungs, or central nervous system, especially in patients with conditions such as thalassemias, myelofibrosis, hemolytic anemias, and hematological malignancies. This report describes a 26-year-old man with sickle beta-thalassemia and EMH, observed through serial imaging over 2 years. Initial imaging showed paravertebral masses and diffuse skeletal sclerosis on radiography and CT, with MRI revealing lobulated lesions without spinal canal extension. Treatment included radiotherapy and hydroxyurea, leading to fatty replacement in EMH masses, evidenced by changes in MRI characteristics over time. The case provides a longitudinal perspective on EMH. The observed transition from active EMH to fatty replacement underscores the dynamic response to treatment and highlights the importance of serial imaging in managing EMH. This case emphasizes the need for further studies to optimize treatment strategies and improve understanding of EMH progression in hematological disorders.