Teratoma Presenting as An Unilateral Mediastinal Mass with Contralateral Pleural Effusion

A teratoma is the most common benign germ cell tumor that develops in the mediastinum. Patients with a mediastinal teratoma are usually asymptomatic. However, a spontaneous rupture of a mediastinal teratoma into the pleural cavity or adjacent organs can cause severe chest pain, hemoptysis, acute dyspnea, etc. Complications such as recurrent pneumo- nia, pericardial effusion, pleural effusion and great vessel invasion can sometimes occur. We encountered a case of a patient with an abrupt onset of dyspnea after persistent shoulder pain for one month. The X-ray examinations revealed a unilateral mediastinal mass with contralateral pleural effusion. Subsequent evaluations confirmed a spontaneous ru- pture of the teratoma into the contralateral pleural cavity. (Tuberc Respir Dis 2006; 60: 347-352)