[Cysts of the thoracic canal. Apropos of a subclavicular site]

The authors report a case of cystic dilatation of the terminal portion of the thoracic duct which clinically corresponded to a swelling in the root of the left side of the neck. Pathogeny and evolutive mode of this exceptional affection are ill known. Echography and scanography show the cystic nature of the mass. Diagnosis is made by direct puncture which can prove the chylous nature of the content and permits the opacification of the cyst. Lymphography shows the type of junction with the thoracic duct.