Cord compression due to extramedullary hematopoiesis in two patients of beta -thalassemia intermedia

ABSTRACT

Thalassemia is the most important hemoglobinopathy in Khuzestan province. Thalassemia intermedia [TI] is a genetically heterogenous disease and can result from many different genetic lesions. We report two cases of TI-EMH caused by two separate mechanism and their successful management. Magnetic Resonance Imaging [MRI] is the best diagnostic method in these cases. Management can be done via Transfusion therapy, Radiotherapy, Hydroxyurea [HU], and Surgery. A 17 years old girl with beta-TI previously asymptomatic presented with back pain and leg weakness which started one month ago. The other patient was 25 years old man referred to hospital with back pain, paresthesia, urine frequency and impairment of gait. In the first case the cause of cord compression was the osseous expansion while in the second patient it was related to soft tissue EMH. First patient was successfully treated with low dose radiotherapy and HU. Radiotherapy was initiated with 200cGY fractions to a total dose of 1600cGY and HU 10mg/kg/day. At the end of radiotherapy, the patient was ambulatory with mild residual weakness. She was regularly followed for two years; at present she is active and asymptomatic. The second patient was successfully treated with low-dose radiotherapy and HU. Radiotherapy was started in 200cGY fractions to a total dose of 1600cGY and HU was given at 10mg/kg/day. At the end of radiotherapy the patient was ambulatory with mild residual weakness. He was regularly followed for six months. At his last visit, he was able to walk and climb stair without any assistance. His neurological examination was much better than before. The most common site of spinal epidural extramedullary hematopoiesis is the posterior aspect in the thoracic spine. EMH can be prevented by regular transfusion therapy which corrects anemia and thereby abolishes the stimulus for EMH. Surgical decompression is the method of choice for the management of EMH because histological diagnosis can be established and immediate decompression of the mass can be achieved. This is especially important to decompress the spinal cord quickly in patients with epidural mass caused by EMH. The disadvantages of surgical intervention include risk of excessive bleeding due to high vascularity of the mass and higher incidence of recurrence. In areas where thalassemia is prevalent, EMH should be considered in the differential diagnosis of patients who have chronic anemia with an intrathoracic mediastinal mass