Cancer-related Stroke due to Mural Thrombus in the Extracranial Carotid Artery

A 41-year-old man was admitted to our hospital because of a cancer-related stroke (CRS) caused by a thrombus of the extracranial carotid artery. He had undergone neoadjuvant radiochemotherapy for metastatic colorectal adenocarcinoma. The serum D-dimer values were within the normal range. We treated him with intravenous unfractionated heparin followed by warfarin. There were no recurrent stroke events over six months. The leading cause of a CRS is an embolism caused by hypercoagulopathy, mainly represented by non-bacterial thrombotic endocarditis. However, it was unusual that, in the current case, a thrombus of the extracranial carotid artery was formed with no significant residual stenosis, thus resulting in an artery-to-artery embolism.