[Castleman disease in the posterior mediastinum showing atypical feature in computed tomography; report of a case].

A 41-year-old man was referred to our hospital because of an abnormal mass on a chest X-ray. An enhanced computed tomography (CT) showed a well-defined round mass (30 x 45 x 66 mm in diameter) that was heterogeneously enhanced owing to central necrotic or cystic change. A 3-dimensional CT demonstrated a couple of feeding arteries to the mass. The mass was completely resected through thoracotomy. Dissection of tight adhesion between the hypervascular mass and the surrounding tissues caused relative amount of hemorrhage during the surgery. The cystic lesion of the mass was fulfilled with brown liquid. The pathological examination revealed the mass as Castleman disease, and scattered cells in the cystic lesion.