Surgical resection of a giant pericardial cyst showing a rapidly growing feature

This report presents an extremely rare case of a rapidly growing giant pericardial cyst which was surgically removed 20 years after the first detection. A 38-year-old asymptomatic male was referred because of rapidly growing mass on the right diaphragm. This lesion was detected about 20 years earlier and checked by a chest roentgenogram once a year. However, this lesion showed rapid growth over the last year, therefore surgical removal was performed. A pathological examination revealed this lesion as a giant pericardial cyst without inflammatory, hemorrhage or malignant cells. Therefore, there was no pathological explanation for the rapid growth of this cyst. In conclusion, general thoracic surgeons should be aware of the possibility of rapid growth, even if the diagnosis is a pericardial cyst.