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.