Clear Cell Tumor of the Lung Showing Gradual Growth for 6 years

: Clear cell tumor of the lung (CCTL) is a rare benign tumor that originates from the lung. We report a case of CCTL which had grown for 6 years. The patient was a 25-year-old woman and her chest roentgenogram detected a well-circumscribed coin-like shadow in the left lower lung field. Its size was 30 mm in diameter at consultation, and retrospectively we recognized a nodule of 13 mm in diameter in the same location on the health checkup roentgenogram 6 years before. The growth of the tumor suggested the possibility of malignancy, and the tumor was surgically resected by partial resection of the lung. Post operative course was uneventful. The tumor was clearly separated from pulmonary parenchyma, and was immunohistochemically diagnosed as CCTL.