[A case of mature teratoma perforated into the pericardial cavity].

A case of a 35-year-old woman with mature teratoma which was perforated into the pericardial cavity, was reported. She was admitted to our hospital for surgical treatment of anterior mediastinal tumor. On her 6th hospital day, she had high fever. A chest X-ray and UCG showed cardiomegaly and pericardial effusion. We diagnosed her as perforated teratoma into the pericardial cavity and the emergent operation was performed. The tumor adheeded to pericardium and a large quality of bloody effusion was found in the pericardial cavity. The tumor was removed with pericardium immediately. In this case, the mechanism of perforation was thought to be caused by infection and massive fluid influx into the cyst.