Cancer‐related thrombotic microangiopathy and disseminated intravascular coagulation in a patient with bone marrow carcinomatosis of unknown primary origin: A case report

Abstract

Abstract Background Cancer‐related thrombotic microangiopathy (CR‐TMA) is a rare type of Coombs‐negative hemolytic anemia, which is caused by malignancy and has a poor prognosis. Case A 76‐year‐old female was referred to our hospital due to Coombs‐negative hemolytic anemia, which was causing fatigue and dyspnea on exertion, accompanied by schistocytosis. A bone marrow examination demonstrated bone marrow carcinomatosis, and the tumor cells were morphologically suspected to be signet‐ring cell carcinoma cells. As we failed to find the primary tumor site before the patient died, she was diagnosed with CR‐TMA due to bone marrow carcinomatosis of unknown primary origin. Thrombotic thrombocytopenic purpura (TTP) was rapidly ruled out based on her PLASMIC score. In addition, immunohistochemical staining of a clot section of the bone marrow and tumor marker data were useful for narrowing down the likely primary tumor site. Conclusion Although CR‐TMA is an extremely rare phenomenon, clinicians who suspect CR‐TMA should quickly rule out TTP and decide whether to provide appropriate chemotherapy or plan for palliative care.

Keywords

• bone marrow carcinomatosis
• Cancer‐related thrombotic microangiopathy
• carcinoma of unknown primary
• PLASMIC score