CASE 13669 Published on 13.06.2016

Intrathoracic extramedullary haematopoiesis and skeletal involvement in a case of thalassaemia intermedia


Chest imaging

Case Type

Clinical Cases


Eleonora Tricarico1, Raffaella Peschechera2, Francesco Tricarico3

(1) University of Bari Medical School,
DIM - Section of Diagnostic Imaging;
Piazza Giulio Cesare 11
70124 Bari, Italy;
(2) P. O. Di Venere, Dpt of Diagnostic Imaging,
Via Ospedale Di Venere, 70131,
Carbonara di Bari, Italy
(3) P. O. San Paolo, Dpt of Diagnostic Imaging,
Via Caposcardicchio, 70123,
Bari, Italy

25 years, male

Area of Interest Haematologic ; Imaging Technique Conventional radiography, CT
Clinical History
A 25-year-old boy affected by thalassemia intermedia underwent regular follow-up. The patient was asymptomatic, regularly received transfusions and was positive for HCV. A routine chest radiograph was performed.
Imaging Findings
Chest radiograph revealed a peripheral right basal opacity abutting the costal arches and bilateral well-defined opacities overlying the spine (Fig. 1). A chest CT (computed tomography) was ordered for further characterization, which showed multiple bilateral well-marginated paravertebral and pericostal soft tissue masses demonstrating mild enhancement after intravenous injection of contrast medium (Fig. 2). A moderate amount of soft tissue diffusely surrounded the sternum (Fig. 2b, 2c, 4b). A diffuse structural remodelling of ribs, vertebral bodies, sternum and scapulae was also seen, consisting of rib widening, destruction of medullary trabeculae with trabecular thinning and multiple cortical interruptions, especially in the costal arches adjacent to the soft tissue masses (Fig. 3, 4). The diagnosis of extramedullary haematopoiesis and skeletal abnormalities related to bone marrow expansion was made.
Thalassemia is a chronic, inherited, microcytic anaemia characterized by a defective haemoglobin synthesis associated with ineffective erythropoiesis, leading to bone marrow hyperplasia and extramedullary haematopoiesis, which represents the proliferation of hematopoietic cells outside of the bone marrow [1].
Extramedullary haematopoiesis (EMH) usually involves liver, spleen and lymph nodes, but other possible locations are thorax and kidneys. Uncommon locations are skin, central nervous system and adrenal gland [3].
Bone marrow hyperplasia leads to skeletal changes characterized by expansion of the medulla, cortical thinning and resorption of trabecular bone, with loss of bone density that causes a greater risk of fracture [1, 2]; these bone anomalies manifest with a typical widening of the ribs. Secondary cortical breaks may occur because of the expanded bone marrow and could also be attributed to the presence of adjacent foci of erythropoietic tissue. In fact, the presence of masses of EMH adjacent to bone and cortical bone disruption are strongly related [4]. Our patient suffered from thalassaemia intermedia and presented diffuse skeletal anomalies with multiple cortical interruptions that were associated with the adjacent masses of intrathoracic extramedullary haematopoiesis.
Intrathoracic EMH is characterized by paraosseous masses adjacent to the vertebrae (frequently bilaterally), ribs (commonly multiple), or both, and may also manifest with interstitial lung changes and haemothorax, either alone or in combination. The presence of paraosseous mass is more frequent in thalassaemia than in other causes of intrathoracic EMH [5]. Chest radiograph reveals smooth or lobulated paraspinal or rib masses. On CT images, paraspinal EMH may manifest with isolated or multiple mediastinal masses. Occasionally these can be continuous with abdominal paraspinal masses. The lesions may present mild enhancement, which may be heterogeneous in long-standing lesions representing iron deposition and fat infiltration [3]. Magnetic resonance imaging is an accurate technique in characterization of intrathoracic EMH, showing with great detail both the topography and extent of the masses; in T1 and T2 weighted images, active lesions show intermediate signal intensity, while inactive lesions may reveal high signal intensity in both sequences because of fatty infiltration or low signal intensity secondary to iron deposition [6].
EMH may be asymptomatic or present with symptoms related to the mass-effect of the lesions [5].
The diagnosis of EMH is more straightforward when the lesions are multifocal or bilateral, or present iron deposition or fatty replacement, while in EMH manifesting as a single mass, differentiation form neurogenic or mesenchymal tumour may be challenging and may require biopsy [6].
Differential Diagnosis List
Intrathoracic extramedullary haematopoiesis associated with skeletal involvement in thalassaemia intermedia
Neurogenic tumour (for EMH)
Mesenchymal tumour (for EMH)
Lymphadenopathy (for EMH)
Metabolic bone diseases (for skeletal abnormalities)
Multiple myeloma (for skeletal abnormalities)
Final Diagnosis
Intrathoracic extramedullary haematopoiesis associated with skeletal involvement in thalassaemia intermedia
Case information
DOI: 10.1594/EURORAD/CASE.13669
ISSN: 1563-4086