[Solitary renal cell carcinoma metastasis to the thyroid gland--a paradigm of metastasectomy?].

We investigated the usefulness of thyroidectomy for solitary metastases from renal cell carcinomas in ten patients. In the absence of postoperative morbidity and mortality, a mean survival time of 3.4 years was observed. Subsequently, four patients developed intracerebral metastases. Swelling of the neck and the discovery of a nodule in the thyroid of patients who have undergone nephrectomy for renal cell carcinoma should raise suspicion of a metastasis, possibly after a long latency period. With the aid of modern immunohistochemical methods, renal cell carcinoma metastasis can now be identified unequivocally, with differentiation from a primary follicular carcinoma of the thyroid rendered possible by a combination of TTF-1, thyroglobulin, and CD 10. In the event of a solitary lesion with no extrathyroidal tumour manifestation, an R0 resection of the metastasis should always be attempted. If tumour dissemination has occurred, palliative measures and endoscopic intervention (e.g. placement of an endotracheal stent) with the aim of improving quality of life by preventing obstruction of the airways are justified.