A case of papillary thyroid carcinoma with renal and pulmonary metastases

Distant metastases derived from papillary carcinoma are generally detected in the lungs and bones. However, renal metastasis is rare. We herein report a case of papillary thyroid carcinoma with renal and pulmonary metastases that had been initially diagnosed as primary renal carcinoma with pulmonary metastases. The lesions showed response to immune checkpoint inhibitors and tyrosine kinase inhibitor but not to radioactive iodine therapy.