[Solitary pulmonary metastasis of papillary thyroid carcinoma 37 years after thyroidectomy]

Though papillary thyroid carcinoma is likely to metastasize to the lung, solitary pulmonary metastasis is uncommon. We report a case of a 69-year-old woman with a solitary pulmonary metastasis of papillary thyroid carcinoma. She had a history of thyroidectomy for papillary thyroid carcinoma at the age of 31. A nodule in the right lung was unexpectedly found by computed tomography (CT), which was suspected of the primary lung cancer. Surgical biopsy was performed, and the pathological diagnosis was pulmonary metastasis of papillary thyroid carcinoma. The possibility of metastatic tumors should be taken into consideration when the patient has a history of malignant disease even if long time goes by.