[A case report of asymptomatical large carinal bronchial cyst].

A 36-year-old man with a mediastinal bronchial cyst was reported. CT showed a mass with water density in the posterior mediastinum. MRI revealed that this mediastinal mass had high signal intensity on both T1-weighted and T2-weighted images. MRI was considered to be useful for the qualitative diagnosis of mediastinal tumors as cystic or solid. An operation was performed and histological diagnosis was bronchial cyst. Intracystic fluid study revealed high titer of total protein, amylase and tumor markers, low titer of glucose and LDH.