Solitary intrathyroid metastasis of renal cancer.

In general, it is estimated that around 1% of all clinically detectable thyroid cancers are of metastatic origin. With regard to the origin of the metastatic thyroid lesions, the most common primary sites are tumors of kidneys, breast, lungs and gastrointestinal system, and melanomas. Patients with nodular goiter and history of malignancy should be stratified into a high risk category. The authors present a patient with solitary thyroid metastasis from renal clear cell carcinoma 31 and 11 years after left and right nephrectomy and present a comprehensive review of the literature (Fig. 3, Ref. 14).