Renal cell carcinoma with metastasis to the thyroid gland.

Cancers that metastasize to the thyroid gland are uncommon. Metastasis to the thyroid gland has been reported in renal cell carcinoma (RCC), breast cancer, lung cancer, gastrointestinal malignancies, malignant melanoma, sarcoma, hematologic malignancies, and other genitourinary cancers. A computer search of the records of the department of pathology at Loyola University Medical Center was done to determine the number of thyroidectomies performed between 1988 and 1998. A detailed review of the clinical records of patients with metastasis to the thyroid gland from RCC was done. A total of 941 thyroidectomies were performed between 1988 and 1998. Metastasis to the thyroid gland was seen in six cases (0.64%). Three of these six cases had metastasis from RCC. The interval between the diagnosis of the primary RCC and the thyroid metastasis was 2 to 10 years. Two of these three patients had an adenomatous thyroid gland. Metastases to the thyroid, though relatively rarely diagnosed clinically as a cause of thyroid nodule, must be considered in the differential diagnosis of thyroid nodule, particularly in patients who have a history of RCC.