A 71-year-old woman was referred to our hospital for a round mass shadow in the right lower lung field in mass screening chest X-ray. Computed tomography (CT) of the chest showed a well-defined lobulating mass shadow measuring 2.2 cm in diameter in the lower lobe of the right lung and a ground glass opacity ( GGO) in the upper lobe of the left lung. She underwent video-assisted partial resection of right lower lobe of the lung. The pathological examinations indicated a pulmonary metastasis of follicular thyroid carcinoma. Three months later, video-assisted partial resection of left upper lobe of the lung was performed. Microscopically, 2 lesions of adenocarcinoma in situ were revealed.