Abstract

Background: Extramedullary hematopoiesis (EH) is common in patients with ineffective erythropoiesis like thalassemia major (TM). EH commonly involves intra-abdominal organs (e.g., spleen and liver), but rarely involves vertebral bodies. Here, we reviewed images of EH contributing to spinal canal stenosis.

Case Description: A 19-year-old male with beta-thalassemia major (TM) presented with pain and bilateral lower extremity neurogenic claudication. Bilaterally, on examination, he had positive straight leg raising to 30°, a loss of the Achilles responses, and decreased pain appreciation in the L5S1 distributions. The lumbar MR showed anterior epidural lobulated mass lesions at L5 and S1, contributing to marked canal stenosis. Following an L5/S1 laminectomy for decompression, the biopsy revealed extramedullary hematopoietic tissue.

Conclusion: Patients presenting with the lower extremity symptoms/signs, ranging from low back pain to neurogenic claudication and even paraplegia, may have EH secondary to TM. Treatment options include hypertransfusion, local radiation therapy, and/or surgical decompression.

Keywords: Beta-thalassemia, Extramedullary hematopoiesis, Radiculopathy, Spinal stenosis

INTRODUCTION

Extramedullary hematopoiesis (EH) is observed in many hemoglobinopathies, including beta-thalassemia major (TM). Here, we report a patient with TM who, while receiving chronic transfusions, developed epidural EH resulting in spinal canal stenosis at the L5/S1 level requiring operative decompression.

CASE DESCRIPTION

A 19-year-old male with beta-TM complicated by chronic iron overload, presented with bilateral lower extremity pain, numbness, and neurogenic claudication. Bilaterally, on examination, he had positive straight leg raising to 30°, a loss of the Achilles responses, and decreased sensation in the L5-S1 distributions. When the lumbar MR demonstrated L5S1 EH responsible for spinal canal stenosis [ Figure 1 ], the patient underwent an L5S1 laminectomy; postoperatively, all preoperative symptoms and signs resolved. The histopathological evaluation of the EH mass revealed hyperplastic hematopoietic tissue.

Figure 1:

(a and b) Sagittal T2-weighted images showing L5, S1 level anterior epidural hypointense lobulated mass lesion attached to the posterior surface of the vertebral body with severe canal stenosis. (c and d) Axial T2-weighted images showing bi-lobulated lesion protruding from the vertebral body with near total canal stenosis.

DISCUSSION

Location and frequency of occurrence of spinal EH with TM

EH has a prevalence in transfusion-dependent beta-thalassemia of <1%.[ 4 , 6 ] EH typically occurs systemically (e.g., in many abdominal and/or thoracic organs). In the central nervous system (CNS), it commonly involves the choroid plexus, cranial dural folds, and peripheral nerves and can even be found within some brain tumors.[ 1 ] In the spinal canal, EH often involves contiguous vertebral bodies and can extend into the spinal canal where it may presents as a pseudotumor.[ 2 ]

Differential diagnosis and MR findings of EH with TM

The differential diagnoses for EH spinal lesions include an epidural infection, vertebral fracture, or epidural hematoma.[ 3 ] MRI, the study of choice, frequently demonstrates a lobulated hypointense mass dorsal to a vertebral body that does not enhance with contrast.

Treatment options for EH with TM

Treatment of EH with TM include; hypertransfusion, local radiation therapy, and/or surgical decompression. Blood transfusions can prevent further progression of EH pseudotumor.[ 5 ] Radiotherapy reduces the volume of pseudotumor, thus relieving local compressive symptoms/signs. Surgery, such as decompressive laminectomy, offers immediate relief of cord compression, and/or canal obstruction.[ 1 , 3 ]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Amirjamshidi A, Abbassioun K, Ketabchi S. Spinal extradural hematopoiesis in adolescents with thalassemia. Childs Nerv Syst. 1991. 7: 223-5

2. Chehal A, Aoun E, Koussa S, Skoury H, Koussa S, Taher A. Hypertransfusion: A successful method of treatment in thalassemia intermedia patients with spinal cord compression secondary to extramedullary hematopoiesis. Spine (Phila Pa 1976). 2003. 28: E245-9

3. Munn RK, Kramer CA, Arnold SM. Spinal cord compression due to extramedullary hematopoiesis in beta-thalassemia intermedia. Int J Radiat Oncol Biol Phys. 1998. 42: 607-9

4. Taher A, Isma’eel H, Cappellini MD. Thalassemia intermedia: Revisited. Blood Cells Mol Dis. 2006. 37: 12-20

5. Taher A, Vichinsky EP, Musallam K, Cappellini MD, Viprakasit V, Thalassaemia International F.editors. Guidelines for the Management of Non Transfusion Dependent Thalassaemia (NTDT). Cyprus: Thalassaemia International Federation; 2013. p.

6. Taher AT, Musallam KM, Karimi M, El-Beshlawy A, Belhoul K, Daar S. Overview on practices in thalassemia intermedia management aiming for lowering complication rates across a region of endemicity: The optimal care study. Blood. 2010. 115: 1886-92