Thyroid metastases from clear cell renal carcinoma 18 years after nephrectomy.

Single or multiple thyroid metastases from extra-thyroid primary tumors are reported to be rare. Malignancies that metastasize to the thyroid include cancers originating from lung, breast and kidney. We report our experience with a case of thyroid metastases, which were detected 18 years after curative kidney surgery for renal cell carcinoma. After 18 years, the patients noted the sudden appearance of a lump in the neck. Ultrasonography showed the presence of a multinodular goiter, all nodules being "cold" at scintiscan. Total thyroidectomy was performed; histology of all nodules revealed a metastatic thyroid cancer from renal cell carcinoma. The patient was still alive and in good health 16 months after thyroidectomy. History of patients with thyroid nodules should include inquiring about extra-thyroid malignancies, especially renal cell carcinoma, that may have been diagnosed even many years earlier. As a corollary, follow-up of such patients should include periodic thyroid exploration or at least a physical examination.