Effect of hydroxyurea on extramedullary haematopoiesis in thalassaemia intermedia: case reports and literature review A. MEO*, E. CASSINERIO † , R. CASTELLI ‡ , D. BIGNAMINI † , L. PEREGO † , M. D. CAPPELLINI † CASE REPORT 1 A 48-year-old woman thalassaemia intermedia was admitted to the Hereditary Anaemia Centre at the University Hospital in Milan (Italy) in January 2004 for the first time. The clinical report documented that she had been transfused with 500 ml of packed red cells three to four times a year from 9 to 22 years of *Department of Paediatrics, Policlinico G. Martino, University of Messina, Messina, Italy † Department of Internal Medicine, University of Milan, IRCCS Maggiore Hospital, Mangiagalli and Regina Elena Foundation, Milano, Italy ‡ Department of Medicine and Medical Specialities, III Division of Internal Medicine, IRCCS Maggiore Hospital, Mangiagalli and Regina Elena Foundation, Milano, Italy Correspondence: Professor Maria Domenica Cappel- lini, Centro Anemie Congenite - Pad. Granelli, Via F. Sforza n 35, 20122 Milan, Italy. Tel.: +39 02/ 55033358; Fax: +39 02/55033665; E-mail: maria.cappellini@unimi.it doi:10.1111/j.1751-553X.2007.00965.x Received 20 August 2006; accepted for publication 25 June 2007 Keywords Hydroxyurea, intrathoracic extramedullary haematopoiesis, thalassaemia intermedia, tumour- like masses SUMMARY Extramedullary haematopoiesis (EH) is the production of blood cell precursors outside the bone marrow that occurs in various disorders, such as thalassaemia, sickle cell anaemia, hereditary spherocytosis, polycythaemia vera, myelofibrosis and other haematological diseases. In chronic anaemia, it is a physiological response to increased erythropoietin. In some other conditions, such as myeloid metaplasia, polycythaemia vera or chronic myeloid leukaemia, EH is due to a clonal disorder of haematopoiesis that enables progenitor cells to escape from the marrow and lodge in other organs. EH usually involves the liver, spleen and lymph nodes or it can be paravertebral, intrathoracic, pelvic. It is often asymptomatic but can sometimes lead to symptomatic tumour-like masses. Treatment options are still controversial and limited, including hypertransfusion regimen, surgical treatment, radio- therapy and hydroxyurea (HU). We describe intrathoracic and symptomatic pelvic EH masses in a 48-year-old woman and intratho- racic bilateral masses causing respiratory insufficiency with pleural effusion in a 42-year-old male, both affected by thalassaemia interme- dia. Both patients showed a clinical improvement with hydroxyurea therapy and occasional blood transfusions. CASE REPORT INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY Ó 2007 The Authors Journal compilation Ó 2007 Blackwell Publishing Ltd, Int. Jnl. Lab. Hem. 2008, 30, 425–431 425