AmitisGen TECH Dev Group Personalized and Precision Medicine Journal 3115-7874 8 28 2023 03 22 Metastatic Malignancy Presenting as Thrombotic Thrombocytopenia Purpura; Report of Two Cases 1 4 702079 10.22034/pmj.2023.702079 EN Hamid Rezvani Associate professor, Department of Medical Oncology and hematology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mehdi Tabarraee Assistant professor, Department of Medical Oncology and hematology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mojtaba Ghadyani Assistant professor, Department of Medical Oncology and hematology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Seyed Amir Sheikholeslami Department of Medical Oncology and hematology, Imam hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Hamideh Rahmani Assistant professor, Department of Medical Oncology and hematology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Soude Ramezan Nejad Hematology and Oncology fellowship, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Aida Iranpour Assistant professor, Iran university of medical sciences, Tehran, Iran Journal Article 2022 12 09 Background<br>Cancer associated thrombotic microangiopathy (CA-TMA) is a rare diagnosis that while confronting a patient with evidence of microangiopathic hemolytic anemia and thrombocytopenia with normal ADAMTS13 enzyme activity, should be considered. Here we present two cases of cancer associated TMA; breast cancer and gastric cancer.<br>Case presentation<br>Case 1 was a 40-year-old man presented with abdominal pain, icterus and weight loss and laboratory tests revealed microangiopathic hemolytic anemia. He received 6 sessions of plasma exchange under diagnosis of thrombotic thrombocytopenic purpura. Bone marrow biopsy and immunohistochemistry revealed clusters of non-hematopoietic cells suggestive of gastrointestinal adenocarcinoma. Case 2 was a 51-year-old woman whose clinical history and laboratory tests were similar to case 1 except for a breast mass along with axillary lymphadenopathy. Bone marrow examination revealed clusters of non-hematopoietic cells and core needle biopsy revealed invasive lobular carcinoma.<br>Both patients were unresponsive to plasma exchange and case 1 unfortunately shortly died after diagnosis but case 2 is alive and survived after receiving chemotherapy. <br>Conclusion<br>Cancer associated TMA can rarely be seen as the first manifestation of a malignancy and causes a diagnostic dilemma for clinicians.The prognosis of CA-TMA is generally poor and initiatingchemotherapy is the only reliable treatment option. https://www.pmjournal.ir/article_702079_e602ce7764e2d2b05457ab09888b1cd4.pdf