[Hodgkin's disease with a giant thymic cyst].

An asymptomatic 26-year-old male was admitted to our hospital for examination of an abnormal mediastinal shadow on chest X-ray. Chest CT showed a large mass in the anterior mediastinum with marked para-aortic lymph node enlargement. The mass consisted mostly of multiloculated low-density areas surrounded by a rim of enhancing parenchymal tissue. Both the cystic tumor and surrounding lymph nodes were resected. The tumor measured 18 x 10 x 2 cm and contained about 450 ml of straw colored fluid. Pathological examination revealed a thymic cyst, the wall of which was composed of Hodgkin's lymphoma cells and nodular sclerotic lesions containing many lacunar cells and Reed-Sternberg cells.