[A case of mediastinal thoracic duct cyst]

This is a rare case of thoracic duct cyst in 34-year-old woman. She complained of a left supraclavicular mass and admitted our hospital. A clinical examinations were all within normal limit. The chest X-ray and the magnetic resonance imaging examinations revealed a round tumor 65 x 40 mm in diameter with clear margin located at the left upper mediastinum. The slightly dilated thoracic duct was connected to the tumor. The left supraclavicular vein was compressed by the tumor. The cystectomy was performed under diagnosis of thoracic duct cyst by Trap door method on September, 17, 1999. Macroscopically, thin-capsulated elastic soft tumor contained chyle, and it was connected to the thoracic duct and the left jugular vein. The histological diagnosis was thoracic duct cyst. The postoperative course was uneventful, and the patient was discharged 9 days after operation. The patient remains disease-free at 8 months after the operation.