[Intrathyroid metastases from kidney cancers: two case reports].

The thyroid metastasis are under estimated in clinical practice because they are in the vast majority of cases "silent". Over than 50% of clinically apparent metastatic lesions are due to kidney carcinomas. We report two cases of thyroid metastasis from clear-cell renal carcinoma occurred 3 years and 8 years after nephrectomies. The previous history of any type of carcinoma should suggest a possibility of metastasis for every thyroid nodules. Fine-needle aspiration cytology is recommended by some authors. Finally, clear-cell carcinoma metastases seem to have a propensity to occur in abnormal thyroid tissue and further study could be interesting.