Thoracic duct cysts: a rare differential diagnosis.

OBJECTIVE

Cysts of the thoracic duct located in the supraclavicular region are uncommon. To date only 12 cases in this topographic area have been described in the literature. Between 1998 and 2002, 5 patients presented to our department with the primary symptom of a palpable soft left-supracavicular swelling that could be displaced relative to adjacent structures.

SETTING

In each case, sonography showed a hypoechogenic, almost echo-free, distinctly outlined polycyclic structure with distal echo enhancement at the junction of the left internal jugular vein and the subclavian vein. All 5 patients underwent surgery, the cysts were extirpated, and the numerous communicating lymph vessels localized and meticulously ligated. Pathohistologic analysis of the milky, yellowish fluid obtained by intraoperative puncture confirmed the initial suspicion of a thoracic duct cyst in all patients.

CONCLUSION

In the case of left supraclavicular masses, the rare differential diagnosis of a thoracic duct cyst must be considered as a possibility. Sonography as the imaging method of choice is sufficient for primary diagnosis. In addition, a thorax x-ray should be performed in order to exclude an intrathoracic involvement. Surgical extirpation marks the therapy of choice in treating such cysts.