ABSTRACT
Metastasis to the thyroid from distant cancer is rarely diagnosed clinically and renal cell carcinoma is the most common group of neoplasm to metastasize to the thyroid. Papillary thyroid carcinoma is known as the most frequent primary thyroid cancer. But coexistence with metastatic renal cell carcinoma to thyroid and papillary thyroid carcinoma is very rare. We are reporting this highly unusual case of metastatic renal cell carcinoma to thyroid, which harbored papillary thyroid cancer. To our knowledge, this is the first case reported in Korea. A 57-year-old woman presented with hoarseness and palpable anterior neck mass. She had a history of renal cell carcinoma of right kidney, which had been resected 10 years previously and had undergone lower anterior resection due to sigmoid colon cancer 2 months before. Fine needle aspiration cytology suggested follicular neoplasm, and total thyroidectomy was performed. The pathology from the thyroid nodules showed papillary thyroid cancer combined metastatic renal cell carcinoma.