Cancer-related thrombotic microangiopathy in a patient with late-stage breast cancer and bone marrow metastasis: a case report and literature review

Introduction Thrombotic microangiopathy (TMA) is a group of diseases characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ dysfunction. Cancer-related thrombotic microangiopathy (CR-TMA) is a rare but life-threatening complication of malignancy with an extremely poor prognosis. There are no universally accepted diagnostic criteria for diagnosis, based on characteristic features, absence of other causes, and detection of malignancy. Case presentation We report the case of CR-TMA and overt disseminated intravascular coagulation (DIC) in a Chinese woman with late-stage breast cancer and confirmed bone marrow metastases. The patient was severely anemic with thrombocytopenia and progressive multi-organ dysfunction. The laboratory results showed Coombs-negative hemolytic anemia with schistocytes, a markedly elevated lactate dehydrogenase, and CDSS score of 9 indicating overt DIC. Normal ADAMTS13 activity and negative anti-ADAMTS13 antibodies excluded thrombotic thrombocytopenic purpura. Atypical hemolytic uremic syndrome, drug-induced TMA, infection-associated TMA, and catastrophic antiphospholipid syndrome were also excluded. The diagnosis of CR-TMA with concomitant overt DIC was established. Despite supportive care, she rapidly deteriorated and died on day 6. Conclusion This case illustrates the diagnostic difficulties of CR-TMA, especially since it overlaps with DIC in advanced malignancy. Breast cancer is the second most common underlying malignancy associated with CR-TMA. Survival is very poor and median survival is less than 1 month. Early detection and prompt anti-tumor treatment are important, although the window of treatment is narrow in patients with extensive metastatic disease.