Renal cell carcinoma metastases to the thyroid gland-8 cases reported

Clinically important, isolated metastases to the thyroid gland is a rare occurrence. Renal cell carcinoma (RCC) is the most common primary tumor site. We report on 8 cases of late onset metachronous thyroid metastases of RCC.

Eight patients presented with metachronous thyroid metastases at a median of 12 years (range 9-18 years) after nephrectomy for RCC. Two patients had simultaneous lung and lymph node metastases, respectively. Four patients had been previously operated for other metastases 1 to 5 years earlier, three of them due to pancreatic metastases. The leading symptom was neck enlargement in all but one case.

Four total thyroidectomies, 3 subtotal resections, and 1 lobectomy were performed. Complete removal of metastases were achieved in all but one case. There was no postoperative morbidity. Six metastases were bilateral, two unilateral. The 4 year overall survival rate following metastasectomy was 53%, median survival from the date of nephrectomy was 21 years.

Long-term survival can be achieved after resection of isolated metachronous RCC metastases to the thyroid gland. Total thyroidectomy is not required, unless it is necessary for complete metastasectomy.