[Thyroid metastasis of a renal carcinoma. 3 clinical cases]

The clinical finding of metastasis to the thyroid is a very rare event. When a metastasis from a renal carcinoma is diagnosed, it is usually the distant evidence of a tumour discovered and removed surgically months or years before, or it may be the first clinical sign of an as yet undiagnosed asymptomatic renal tumour. A case of massive retrosternal goiter in a 65-year-old patient, operated on for a right renal carcinoma (nephrectomy 6 years before), is reported. The goiter, causing compression symptoms and dyspnoea, was treated by total thyroidectomy. The pathological diagnosis was metastasis from renal carcinoma. The authors present a second case of nodular goiter, in a 79-year-old woman, 9 years after a right nephrectomy for a renal carcinoma. The expanding nodule, diagnosed intraoperatively as carcinoma, was treated by total thyroidectomy. The postoperative pathological diagnosis was metastasis from renal carcinoma. The authors report a third case of an expanding nodule of the thyroid, in a 65-year-old patient, diagnosed intraoperatively as a metastasis from renal carcinoma, treated by right lobectomy and isthmusectomy. An abdominal CT scan revealed a renal asymptomatic tumor, treated by right nephrectomy. The diagnosis can be established by means of fine needle aspiration biopsy preoperatively or intra- or postoperative histology. Surgical therapy may resolve the compression symptoms and improve the prognosis.