Reversible paraparesis due to extramedullary hematopoiesis

Key Clinical Message Extramedullary hematopoiesis should be considered in the differential diagnosis of spastic paraplegia in a patient with thalassemia. Radiotherapy remains the treatment of choice, and regain of motor power is expected. Sagittal T2 weighted MRI: (A) thoracic paravertebral lesions—active lesions (red arrow) show intermediate signal intensity while older inactive lesions (white arrow) show high signal intensity due to fatty infiltration; (B and C) narrowing of the spinal canal and compression of the medulla along the thoracic spine by lesions inside the spinal canal (small blue arrows); (C) lumbo‐sacral active sites of extramedullary hematopoiesis (small yellow arrows).