Unusual Presentation of a Cervical Mass Revealed as External Jugular Venous Aneurysm.

Venous aneurysms of the jugular vein are one of the rare causes of neck swelling, and primary venous aneurysms of the external jugular vein are extremely rare. A 46-year-old woman presented with a painless and suddenly growing mass in the left neck. A computed tomography angiography revealed a fusiform venous aneurysm of the external jugular vein containing intraluminal thrombus. We performed resection of the aneurysm and ligation of the external jugular vein. Removal of the aneurysm of the neck vein was necessary because venous aneurysms with thrombosis may lead to serious thrombotic complications such as pulmonary embolism.