Thoracic duct cyst of the neck: a case report.

A thoracic duct cyst was excised from the left side of the neck of a 63-year-old woman. It was 6.5cm in length and 3.5cm in width, and was located behind the common carotid artery and jugular vein. The proximal portion of the thoracic duct with a narrowed lumen was in direct contact with the lateral surface of the cyst and the venous angle. The lower end of the cyst extended into the mediastinum to immediately above the aortic arch; the inferior portion of the thoracic duct descended from the bottom of the cyst into the mediastinum behind the aorta. The cyst was unilocular with a fluid content high in triglyceride (3350mg/dl). Its wall was muscular and permeated with lymphatic vessels.