en Adults Hematology & Oncology Adults Hematology & Oncology گزارش مورد Case report Idiopathic thrombocytopenia purpura (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia and mucocutaneous bleeding. The former has a primary role in the diagnosis and treatment of ITP. One of the leading causes of miscounted platelets in patients who suffer from ITP is giant platelets which may indicate factitiously a severe false thrombocytopenia. Here, a case of macrothrombocytopenia is presented in an ITP patient. Giant platelets of this patient not only resulted in miscounting platelets but also falsely increased reading of RBC counts. By counting platelets through peripheral blood smear and hemocytometer, the patient was saved from an unnecessary splenectomy. Idiopathic thrombocytopenic purpura, Giant platelet, Macrothrombocytopenia, Factitious thrombocytopenia 133 135 http://ijbc.ir/browse.php?a_code=A-10-387-1&slc_lang=en&sid=1 Mohammad Ghorbani sbmu_mohamad@yahoo.com 10031947532846004516 10031947532846004516 No MSc of Hematology and Blood Blanking, Faculty member of Gonabad University of medical sciences, Gonabad, Iran Hamid Reza Niazkar hrn185@hotmail.com 10031947532846004517 10031947532846004517 Yes Medical Student, Student Research Committee, Gonabad University of Medical Sciences, Gonabad, Iran Mohammad Mehdi Ejtehadi jtehadilab@gmail.com 10031947532846004518 10031947532846004518 No Laboratory technical manager,Shahid Hasheminejad Hospital,Mashhad University of Medical Sciences,Mashhad,Irane Reza Mahmoudi mehrnaz.mehraban@yahoo.com 10031947532846004519 10031947532846004519 No Internist specialist,Department of Internal Medicine, Faculty of Medicine, Gonabad University of Medical Sciences Abbasali Abbasnezhad abbasnezhad.abbasali@gmail.com 10031947532846004520 10031947532846004520 No Department of Physiology, Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran