[Benign clear cell tumor of the lung diagnosed by transbronchial biopsy]

A 26-year-old woman had an abnormal shadow on chest X-ray films during a general medical examination. A chest roentgenogram showed a nodular shadow 8 mm in diameter in the middle field of the right lung. Transbronchial biopsy specimens revealed that the coin lesion was a benign clear cell tumor. Benign clear cell tumors of the lung are rare; only 21 cases, including the present case, have been reported in Japan. Although the diagnosis in most of the cases reported required an open thoracotomy, for our patient the diagnosis was based solely on the findings of a transbronchial biopsy.