Thoracic cord compression by extramedullary hematopoiesis in thalassemia

The diagnostic value of magnetic resonance imaging compared to computed tomography in the evaluation of fat-containing thoracic lesions

Intrathoracic fat-containing lesions may arise in the mediastinum, lungs, pleura, or chest wall. While CT can be helpful in the detection and diagnosis of these lesions, it can only do so if the lesions contain macroscopic fat. Furthermore, because CT cannot demonstrate microscopic or intravoxel fat, it can fail to identify and diagnose microscopic fat-containing lesions. MRI, employing spectral and chemical shift fat suppression techniques, can identify both macroscopic and microscopic fat, with resultant enhanced capability to diagnose these intrathoracic lesions non-invasively and without ionizing radiation. This paper aims to review the CT and MRI findings of fat-containing lesions of the chest and describes the fat-suppression techniques utilized in their assessment.

Marrow outside marrow: imaging of extramedullary haematopoiesis

Extramedullary haematopoiesis (EMH) refers to the formation of non-neoplastic blood cell lines outside the bone marrow and is a common incidental finding when patients with haematological disorders are imaged. EMH presenting as mass (tumefactive EMH) has long been a radiological conundrum as it resembles neoplasms. Several imaging findings have been described in EMH, and these vary depending on the activity of the underlying haematopoiesis. The older lesions are easier to diagnose as they often demonstrate characteristic findings such as haemosiderin and fat deposition. In comparison, the newer, actively haematopoietic lesions often mimic neoplasms. Molecular imaging, particularly ^99mTc labelled sulphur colloid scintigraphy, may be helpful in such cases. Although imaging is extremely useful in detecting and characterising EMH, imaging alone is often non-diagnostic as no single mass shows all the typical findings. Hence, a judgement based on the clinical background, combination of imaging findings, and slow interval growth may be more appropriate and practical in making the correct diagnosis. In every case, an effort has to be made in providing an imaging-based diagnosis as it may prevent a potentially risky biopsy. When confident differentiation is not possible, biopsy has to be resorted to. This article describes the causes, pathophysiology, and theories underlying the genesis of EMH, followed by the general and location-specific imaging findings. The purpose is to provide a thorough understanding of the condition as well as enable the clinical radiologist in making an imaging-based diagnosis whenever possible and identify the situations where biopsy has to be performed.

Recurrent thoracic cord compression due to extramedullary haematopoiesis in thalassaemic patients–A case presentation and literature review

Extramedullary haematopoesis (EMH) in thalassaemic patients to result in spinal cord compression is a rare phenomenon. EMH occurs as compensatory sequelae in those with chronic anaemia such as thalassaemia, other congenital haemolytic anaemia, haemoglobinopathies, and myelofibrosis. Common sites of EMH include liver, spleen, kidneys and lymph nodes, but rarely the paravertebral and spinal cord regions. In our literature review, it was found that only case reports and case series have been published. We present a case of recurrent thoracic spinal cord compression caused by EMH in a 32-year-old thalassaemic Chinese man treated with surgical decompression and spinal stabilisation. The key to successful treatment is prompt diagnosis with early clinical suspicion, magnetic resonance imaging and individualised treatment for each patient. Surgical decompression provides immediate neural decompression while subsequent anaemia management may reduce the risk of recurrence. In the present case, a combination therapy of blood transfusion, surgical decompression and radiotherapy has been shown to deliver successful outcomes in such cases.

Lung masses in a thalassemia patient: A diagnostic dilemma

Thalassemia is a common congenital hemolytic anemia in the South Asian subcontinent. This disease is associated with multiple complications, which accumulate as the age of the patient progresses. Extramedullary hematopoiesis (EMH) is a compensatory physiological mechanism for chronic anemia. EMH can occur in different parts of the body and present with varied imaging features, some of which may be misleading. We here describe the case of a 22-year-old male patient with thalassemia who presented with paracardiac lobulated masses on chest X-ray. They were thought to be lung tumors; however, subsequent computed tomography scan of the thorax showed typical features of EMH involving the vertebrae, ribs and sternum. The patient was assured about the appearance of the masses on the chest X-ray. Imaging features of EMH in the thorax has been discussed in detail.

Thalassemia, extramedullary hematopoiesis, and spinal cord compression: A case report

Background:

Extramedullary hematopoiesis (EMH) refers to hematopoiesis outside of the medulla of the bone. Chronic anemia states such as thalassemia can cause hematopoietic tissue to expand in certain locations. We report a case of spinal cord compression due to recurrent spinal epidural EMH, which was treated with a combination of surgery and radiotherapy. Pakistan has one of the highest incidence and prevalence of thalassemia in the world. We describe published literature on diagnosis and management of such cases.

Case Description:

An 18-year-old male presented with bilateral lower limb paresis. He was a known case of homozygous beta thalassemia major. He had undergone surgery for spinal cord compression due to EMH 4 months prior to presentation. Symptom resolution was followed by deterioration 5 days later. He was operated again at our hospital with complete resection of the mass. He underwent local radiotherapy to prevent recurrence. At 2 years follow-up, he showed complete resolution of symptoms. Follow-up imaging demonstrated no residual mass.

Conclusion:

The possibility of EMH should be considered in every patient with ineffective erythropoiesis as a cause of spinal cord compression. Treatment of such cases is usually done with blood transfusions, which can reduce the hematopoietic drive for EMH. Other options include surgery, hydroxyurea, radiotherapy, or a combination of these on a case to case basis.