Science and Education Publishing American Journal of Medical Case Reports 2374-216X 3 11 2015 10 15 Carcinoma Causing Thrombotic Thrombocytopenic Purpura and Myelonecrosis: A Very Rare Event 372 373 EN Ilknur Nizam Mehmet Ali Erkurt Ilhami Berber Mustafa Koroglu Emin Kaya Irfan Kuku Nese Karadag AJMCR20153116 10.12691/ajmcr-3-11-6 2015 7 13 2015 8 7 2015 10 13 We report a case of thrombotic thrombocytopenic purpura (TTP) which was explored to be the clinical presentation of carcinoma. Plasma exchange therapy failed to respond for the patient, so bone marrow aspiration and biopsy were performed to find out the reason of microangiopathic hemolytic anemia. Bone marrow examination revealed non hematopoetic cell infiltration and myelonecrosis. Carcinoma metastasis was demonstrated at bone marrow trephine biopsy. The primary tumor was found at small bowel after scanning for the source of tumor by computerized tomography.