Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 8 2 2014 06 15 41 44 Mehrzad Mirzania Imam Khomini Hospital Complex, Vali-e-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran. Sedigheh Khalili Arak University of Medical Sciences, Arak, Iran. Akbar Hasanpoor Arak University of Medical Sciences, Arak, Iran. Ahmad Reza Shamshiri Hematology-Oncology and Stem Cell Research Center, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 14 Amegakaryocytic thrombocytopenia (AMT) is a rare cause of acquired thrombocytopenia. The pathogenesis and treatment of AMT is not clearly known. Here we demonstrate a 50-year-old man presented with the clinical manifestations of severe thrombocytopenia (7000 platelets/µl) with a marked decrease to absent of megakaryocytes in the bone marrow. The patient did not respond to intravenous immunoglobulin, cyclosporine or high dose prednisone. After the treatment with anti-CD20 antibody (Rituximab), the patient's clinical symptoms and platelet counts improved. https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/420 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/420/377