UCSF

Renal cell cancer rarely metastasizes to the thyroid gland, and it has been reported to present as a solitary mass. We present a case of diffuse thyroid cancer metastases from renal cell cancer. Bilateral internal jugular vein tumor thrombi were also present. To the best of our knowledge, this is the first description of diffuse thyroid metastases from renal cell cancer in the English literature. Renal cell cancer metastases should be considered in the differential of thyroid imaging abnormalities arising in the setting of known renal cell carcinoma, particularly late in the course of disease. This is frequently associated with internal jugular vein thrombi, which should be evaluated with an abnormal thyroid. Thyroglobulin levels are usually normal in such patients.