[Pulmonary metastases from colon cancer and occult thyroid cancer in the same lobe]

A 70-year-old man with a history of surgery for colon cancer was found to have multiple enlarging pulmonary nodules( 2 in the left lower lobe and 1 in the right upper lobe), and was suspected of having pulmonary metastases from colon cancer. He underwent left lower lobectomy, and subsequent histopathological examination revealed that one was a pulmonary metastasis from colon cancer, and the other was a pulmonary metastasis from papillary thyroid cancer. There were no abnormalities in the thyroid gland according to computed tomography and ultrasonography findings. Therefore, the patient was diagnosed with synchronous pulmonary metastases of both colon cancer and occult thyroid cancer in the same lobe. This is an exceedingly rare case;to the best of our knowledge, there has been no report thus far regarding multiple pulmonary metastases from different primary sites.