[A surgical case of mediastinal cystic lymphangioma].

A surgical case of a 33-year-old male with mediastinal cystic lymphangioma is reported. He was referred to our hospital for examination of mediastinal tumor. Chest X-ray film revealed an abnormal shadow in the left aorto-pulmonary window. CT scan of the chest visualized a smooth-walled, homogenous structure of this mass. MRI showed same findings as CT scan but could not suggest further information. He was operated on under the diagnosis of Castleman's lymphoma or thymic cyst. On thoracotomy, a bulging cystic mass was found in the middle mediastinum just beneath the aortic arch. The cyst was completely removed, and his postoperative course was uneventful. Pathological diagnosis was a mediastinal cystic lymphangioma. Cystic lymphangioma usually occurs in the neck, and rarely occurs in the mediastinum. Only about 30 cases of mediastinal cystic lymphangioma have been reported in the Japanese literatures.