Paraspinal Extramedullary Hematopoiesis in a Transfusion-Dependent Beta-Thalassemia Patient: A Case Report

Abstract

Extramedullary hematopoiesis (EMH) is a compensatory mechanism in chronic anemias, such as transfusion-dependent beta-thalassemia (TDT), most commonly affecting the liver and spleen. Paraspinal EMH is rare and may lead to spinal cord compression, resulting in neurological deficits. We present a 26-year-old male patient with longstanding TDT who developed progressive bilateral lower limb weakness, pelvic paresthesia, and acute urinary retention. MRI revealed a bilateral paraspinal mass compressing the dural sac and spinal cord, with concurrent severe myocardial and hepatic iron overload. Given the high operative risk and contraindications to surgery and radiotherapy, treatment included hypertransfusion, dual iron chelation therapy, and hydroxyurea. The patient developed hydroxyurea-induced bone marrow aplasia requiring discontinuation of treatment. Over six months, motor and sensory functions improved, bladder function partially recovered, iron markers decreased, and MRI showed regression of the mass. This case highlights the complexities in diagnosing and managing paraspinal EMH in high-risk TDT patients and supports the effectiveness of individualized conservative therapy.

Keywords: beta-thalassemia; extramedullary hematopoiesis; hydroxyurea; hypertransfusion; iron chelation; paraspinal mass; spinal cord compression.

Figure 1. Sagittal and axial MRI of the lumbar spine showing a left paraspinal mass consistent with extramedullary hematopoiesis

(A) Sagittal T2-weighted MRI of the lumbar spine shows a well-defined paraspinal soft tissue mass at the L4–L5 level (white arrow), causing mild compression of the dural sac and anterior displacement of the spinal cord. (B) Axial T2-weighted MRI confirms the presence of a left paraspinal mass that is isointense to mildly hyperintense relative to adjacent muscle (white arrow), without evidence of vertebral destruction or spinal canal invasion. These imaging features are consistent with extramedullary hematopoiesis in a patient with transfusion-dependent beta-thalassemia.

Figure 2. Bone marrow biopsy histopathology showing hypocellularity with predominant adipose tissue, suggestive of marrow aplasia likely secondary to chronic transfusion therapy in beta-thalassemia

Histopathology of the bone marrow biopsy demonstrating marked hypocellularity with extensive adipocyte infiltration and reduced hematopoietic elements. These findings are consistent with drug-induced marrow aplasia, likely secondary to hydroxyurea therapy in transfusion-dependent beta-thalassemia patient.