Diagnosis: Extramedulary hematopoiesis in the thorax of a patient with ß-thalassemia intermedia.
Thalassemia intermedia is a clinical entity which applies to patients homozygous or compound heterozygous for thalassemia but have a milder clinical phenotype. The affected individuals, in contrary to thalassemia major patients, are not transfusion-dependent.
A number of molecular processes may result in thalassemia intermedia. The commonest causes include compound heterozygosity for mild ß-thalassemia mutations, coinheritence of homozygous ß-thalassemia and a -thalassemia or factors that sustain a permanent Hb F production during adult life.
The diagnosis of thalassemia intermedia is based on the clinical presentation, and so far, any attempt to find well-defined criteria based on age at presentation, and/or adult or fetal hemoglobin levels has failed.
Although benign, the clinical course of thalassemia intermedia is associated with many complications that need clinical awareness and appropriate treatment. One of these complications is the extramedullary hematopoiesis. The produced mass is in fact rapidly growing bone marrow, and therefore, it has a dramatic response to radiotherapy, so that it will be almost completely resolved within a few weeks after the treatment. The trabeculation and widening of ribs in this patient, presence of splenomegaly, history of non-transfusion-dependent microcytic hypochromic chronic anemia, ethnicity, and finally the dramatic response to minimal dose of radiation therapy, are all in favor of thalassemia intermedia.
As was anticipated, further investigation revealed 3.2% Hb A2, and 67% Hb F.
M. Haghshenas,* M.D.,
F. Habibzadeh, M.D.,
K. Vessal, M.D.,
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*Division of Hematology/Oncology and Bone Marrow Transplantation, Department of Internal Medicine, Shiraz, Iran.