Traumatic external jugular vein aneurysm after a kendo thrust (tsuki).

Aneurysm of the external jugular vein is rare, and a traumatic case with a documented mechanism and pathological findings is exceptional. A woman in her 50s sustained a blunt injury to the left anterior neck from a kendo thrust (tsuki). One month later she developed a left cervical swelling. Ultrasound study and computed tomography showed a 2-cm saccular dilatation with a cranial filling defect, indicating partial thrombosis. After 4 months of observation, the aneurysm was resected at the patient's request. Histopathology showed segmental loss of elastic fibers and adventitial rupture without organized thrombus. Recognizing venous injury after a kendo thrust enables timely diagnosis.