A case of intravascular epithelioid hemangioendothelioma occurring 14 years after coil embolization for an extracranial internal carotid artery aneurysm.

Epithelioid hemangioendothelioma (EHE) is a rare neoplasm originating from various organs. The clinical outcome mostly depends on surgical resectability. The authors report an EHE of the extracranial internal carotid artery developed in a 59-year-old male patient 14 years after the intravascular coil embolization for a carotid aneurysm at the same site. Because the lesion was initially diagnosed as regrowth of the thrombosed aneurysm, decision for radical resection was delayed, and the patient died from rapid tumor progression. Differential diagnosis of atypical vascular mass lesions should include neoplasm, because initial radical resection may be the key to achieve a better prognosis.