Renal cell carcinoma metastases to the thyroid gland -- report of 3 cases and review of the literature

Clinically significant, solitary metastasis to the thyroid gland is a rare occurrence. The clear cell carcinoma of the kidney (RCC) is the most common primary tumor site. Late recurrence is a notable feature of renal carcinoma. Solitary metastases in the thyroid gland occur as late as 100-120 months from the date of nephrectomy. There is a clear survival benefit in selected cases if surgical approach to the thyroid metastases is chosen. In those patients who have undergone complete resection, 5-year-survival-rates of 50 % have been reported. We describe 3 cases of surgically treated thyroid metastases of RCC, and review the literature.