[Preoperative diagnosis of a thoracic duct cyst arising in the supraclavicular fossa--surgical case report].

The incidence of cysts of the thoracic duct is very low, and they are reported to account for only 0.0005-0.5% of all mediastinal tumors. As far as we have been able to determine, there have been no more than 24 case reports of the surgical resection of such cysts, including our own. Moreover, lesions of the left supraclavicular fossa as in the present case were noted in only 2 reports from Western countries, and 2 cases can be found in the Japanese literature. We encountered a case of thoracic duct cyst where we were able to make a diagnosis preoperatively by means of needle aspiration, and report it here together with a discussion of the relevant literature. The patient was a 64-year-old woman who was admitted with the chief complaint of pain in the throat and a sense of pressure in the neck. A swelling was noted in the patient's left supraclavicular fossa, and when this was aspirated it yielded approximately 15 cc of yellowish-white, chylous fluid. No hoarseness or dysphagia were noted. CT scan of the thorax revealed a smooth-surfaced tumor extending from the left supraclavicular fossa to the anterior mediastinum. It showed the simple cystic lesion. On the basis of these findings, a diagnosis of thoracic duct cyst arising in the left supraclavicular space was made. Following excision, the patient's postoperative course was favorable.