[A Case of Sigmoid Colon Cancer with Thrombotic Microangiopathy].

A 50's man was referred to our hospital because of sigmoid colon cancer with multiple liver metastases and para-aortic lymph node metastases. Although blood test showed elevated D-dimer(50 μg/mL), there was no significant thrombus in contrast-enhanced CT scan. Since cancer pain and symptoms of bowel obstruction had continued after endoscopic stent placement, we resected primary lesion. Despite anemia and elevated D-dimer level had persisted after the operation, there were no obvious bleeding source nor thrombus. Continuous intravenous heparin infusion was started for hypercoagulability. Then, D-dimer and CRP levels were promptly decreased. Since schizocyte and giant platelets were observed in peripheral blood smear, he was eventually diagnosed with thrombotic microangiopathy as a paraneoplastic syndrome. However D- dimer and CRP levels were re-elevated, and it seemed to be necessary to control cancer progression. Thus, cetuximab monotherapy was started considering his performance status. After starting cetuximab, fever and CRP level were immediately improved. Cetuximab appeared to be very effective, but he died of acute subdural hematoma. Continuous intravenous heparin infusion was supposed to be effective in the treatment of thrombotic microangiopathy along with the management of cancer.