metastatic malignancy presenting as thrombotic thrombocytopenia purpura; report of two cases

Backgroundcancer 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.case presentationcase 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.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. conclusioncancer 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.