A large intrathoracic extramedullary hematopoiesis in alpha-thalassemia: A case report

Abstract

Rationale: Extramedullary hematopoiesis (EMH) is a rare disease characterized by the formation of hematopoietic elements outside the bone marrow driven by several hematological disease. To the best of our knowledge, EMH is relatively common in patient with beta-thalassemia or hereditary spherocytosis but rarely reported in patients with alpha-thalassemia. Here, we discuss a large intrathoracic EMH (measuring 95 mm × 66 mm) without presenting severe complications in alpha-thalassemia along with literature review.

Patient concerns: A 55-year-old Chinese female patient with alpha-thalassemia presented with ipsilateral pleural effusion and low hemoglobin level.

Diagnosis: Lung cancer was suspected at first and the mass was subjected to CT-guided percutaneous mediastinum biopsy and the pathology confirmed the final diagnosis of extramedullary hematopoiesis.

Interventions: Blood transfusion, thoracentesis and regular follow up were scheduled rather than surgical interventions or radiotherapy since our patient did not exhibit significant symptoms.

Outcomes: After 6 months' regular follow up, the patient exhibited no evidence of disease progress.

Lessons: EMH is frequently misdiagnosed and should be differentiated from other masses in thoracic cavity, especially when the underlying hematological disease is discovered. Treatment methods of EMH include surgical resection, hyper-transfusion, hydroxyurea, low-dose radiation or a combination of them.

Figure 1

Chest X-ray findings. A large soft tissue density mass (yellow arrow) in the posterior right lower thorax on a posteroanterior chest radiography.

Figure 2

Chest CT findings. Extramedullary hematopoiesis present as a 95 mm × 66 mm well-marginated mass (white arrow) in the postero-inferior mediastinum on a chest computed tomography scan.

Figure 3

Bone marrow aspirate analysis. A bone marrow aspirate analysis revealed bone marrow especially erythroid is hyperplasia (G: E was decreased, the relative proportion of immature red blood cells was also increased), and adipose tissue accounts for 15% of the medulla area.

Figure 4

A and B. Percutaneous mediastinum biopsy. The main components were hematopoietic tissue, including hematopoietic cell lines, erythrocytes and megakaryocytes. Furthermore, G: E was decreased and the erythroid lineage was obviously proliferated, which are mainly in the intermediate and late juvenile stage, while the number and morphology of megakaryocytes were normal, and no lung tissue was found. 1. Harteveld, CL and Higgs DR, Alpha-thalassaemia. Orphanet J Rare Dis, 2010. 5:13. 2. Niggemann, P., et al., Fifteen-year follow-up of a patient with beta thalassaemia and extramedullary haematopoietic tissue compressing the spinal cord. Neuroradiology, 2005. 47(4):263–6. 3. Tai SM, et al., Successful treatment of spinal cord compression secondary to extramedullary hematopoietic mass by hypertransfusion in a patient with thalassemia major. Pediatr Hematol Oncol, 2006. 23(4):317–21.