Paraspinal extramedullary hematopoiesis in patients with thalassemia intermedia

Abstract

Ineffective erythropoiesis in patients with thalassemia intermedia drives extramedullary hematopoietic tumor formation in several parts of the body. Paraspinal involvement has received increasing attention due to the associated morbidity secondary to spinal cord compression. Although the history and physical examination may help narrow the differential diagnosis, radiographic imaging remains essential to confirm the existence of hematopoietic tissue. Characteristic appearance has been observed mainly on magnetic resonance imaging. Several treatment options have been described, including transfusion therapy, laminectomy, radiotherapy, and the use of fetal hemoglobin inducing agents that decrease the hematopoietic drive. However, the ideal management scheme remains controversial. Until large prospective trials evaluate the efficacy and safety of the available treatment options, both in single and in combination therapy, an individualized approach should be entertained.

Fig. 1

Pathophysiology of transfusion-independent thalassemia intermedia leading to extramedullary hematopoiesis in various sites within the body including the spine

Fig. 2

Age and gender distribution for reports describing thalassemia intermedia patients with paraspinal extramedullary hematopoiesis [, –, –, –69]

Fig. 3

Imaging of extramedullary hematopoiesis. a Chest X-ray demonstrating expanded anterior rib ends consistent with medullary hyperplasia. A paraspinal mass is seen in the right lower zone (white arrow). With permission from reference [62]. b Computed tomography scan showing inactive paraspinal extramedullary hematopoietic lesion with increased density compared to soft tissue due to iron deposition (black arrowheads). With permission from reference [18]. c Magnetic resonance image of cervical and thoracic spine. T2-weighted sagittal image showing thoracic cord compression by extramedullary intraspinal epidural hematopoietic mass from T2 to T10 (white arrows). With permission from reference [83]

Fig. 4

Recommended treatment algorithm for paraspinal extramedullary hematopoiesis in thalassemia intermedia based on reviewed evidence