[Recurrent bronchogenic cyst--a case report].

Mediastinal bronchogenic cyst is a benign tumor and occupied about 5% of mediastinal tumor in Japan. As a benign tumor, recurrence of bronchogenic cyst is very rare, and we found only 2 cases were reported. We experienced a recurrent bronchogenic cyst found 14 years after first operation. The patient was 56-year-old male, and admitted to our hospital for further evaluation of his abnormal shadow on chest roentogenogram. He had no symptoms. He was operated an bronchogenic cyst for 14 years ago. Chest X-ray, CT, and MRI demonstrated a paratracheal cystic mass which was suspected of a recurrent bronchogenic cyst. An operation was done, and the tumor was resected. A histopathological study showed that the tumor had thin wall and had a ciliated epithelium, then it was diagnosed bronchogenic cyst. The most likely explanation for the recurrence in our patient is an incomplete resection during the initial operation. It is though that only a very small amount of epithelial tissue need remain for recurrence. For prevention of recurrence, complete resection of cyst is necessary, and long-term follow-up is indicated to detect recurrence.