Cortical bone invasion in non-transfusion-dependent thalassemia: tumefactive extramedullary hematopoiesis reviewed.
OBJECTIVE
To assess the prevalence of cortical bone invasion (CBI) with secondary extramedullary hematopoiesis (EMH) in patients with non-transfusion-dependent thalassemia (NTDT), to determine its predilection sites on thoracic and abdominal imaging, to determine whether there is an association between various clinical and hematological parameters, and to evaluate its various findings mainly on magnetic resonance imaging (MRI), in addition to computed tomography (CT) scans.


METHODS
This is a retrospective cohort study of 57 patients with NTDT imaged by CT or MRI. Both clinical and laboratory data were gathered. An imaging scoring system was used to describe the appearance of CBI by MRI.


RESULTS
Twenty-seven patients (47.4 %) were found to have CBI and EMH with the most common location being the thoracic spine. Splenectomy and lower hemoglobin level were found to be independent risk factors for its development. Most lesions were homogenous (70 %), had predominant red marrow signal (67 %), and well-defined margins (89 %).


CONCLUSIONS
CBI and secondary tumefactive EMH are common findings in patients with NTDT, with distinct imaging and clinical characteristics. An increased risk was seen in patients with splenectomy and lower hemoglobin. The imaging scoring system described is helpful in diagnosing and describing this entity, hence precluding unnecessary biopsies.
Division of Orthopaedic Surgery, Department of Surgery, American University of Beirut Medical Center, Beirut, Lebanon.
Karim Z
KZ
Masrouha
Department of Diagnostic Radiology, American University of Beirut Medical Center, P.O. Box 11-0236, Riad El-Solh, Beirut, 1107 2020, Lebanon.
Joelle
J
Wazen
Division of Hematology-Oncology, Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
Anthony
A
Haddad
Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
Fadi
F
Saadeh
Division of Hematology-Oncology, Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
Ali
A
Taher
Department of Diagnostic Radiology, American University of Beirut Medical Center, P.O. Box 11-0236, Riad El-Solh, Beirut, 1107 2020, Lebanon. nk01@aub.edu.lb.
Nabil J
NJ
Khoury
D000293:Adolescent; D000328:Adult; D002648:Child; D003287:Contrast Media; D000071538:Cortical Bone / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006411:Hematopoiesis, Extramedullary; D006801:Humans; D007472:Iohexol; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013789:Thalassemia / Q000150:complications*; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D007472:Iohexol
Cortical bone invasion; Extramedullary hematopoiesis; Non-transfusion-dependent thalassemia; Soft tissue lesion