The patient a 24-year-old male, was shown to have milliary shadows on chest radiographs from the age of 20. He was temporarily treated for pulmonary tuberculosis without success. He had left thyroid mass and lymph node metastases in neck CT scan which was taken after admission but fine needle aspiration result in scanty cellularity. He underwent total thyroidectomy with left modified radical neck dissection and right selective neck dissection under the impression of differentiated thyroid cancer with bilateral neck metastases. Then he underwent 131I ablation treatment and postoperative whole body 131I scintigraphy revealed diffuse intensive uptake in the bilateral lung fields, demonstrating that the pulmonary lesions were metastases of the thyroid cancer.