CASE REPORTS   

Otorinolaringologia 2008 December;58(4):197-200

Copyright © 2008 EDIZIONI MINERVA MEDICA

language: Italian

A case of thyroid metastasis after nephrectomy. A review of the literature

Abbate G. ¹, Dosdegani R. ², Lancella A. ¹, Bagnato R. ³, Foscolo A. ³, Scotti A. ¹

¹ S. C. di Otorinolaringoiatria e Patologia Cervico-Facciale Ospedale “S. Biagio”, Domodossola, Italia 2 S. C. di Otorinolaringoiatria e Patologia Cervico-Facciale Ospedale “S. Andrea”, Vercelli, Italia 3 Servizio di Anatomia Patologica Ospedale “Castelli”, Verbania, Italia

Although thyroid metastases are common in autopsy studies, clinically significant metastases are rare; the renal carcinoma is the most common primary tumor site. Thyroid metastasis can be the initial presentation of renal cancer or it may occur a long time after nephrectomy, which can lead to misdiagnosis of primary thyroid neoplasm. Most thyroid metastases (80%) occur within 3 years from primary tumor resection, but in case of renal cell carcinoma (RCC) they can occur as late as 19 years. The diagnosis of metastatic thyroid disease should be suspected in patients with even a remote history of renal cancer. In the presence of a clear cell tumor of the thyroid gland, the diagnostic considerations must include metastatic RCC. Fine needle aspiration biopsy (FNAB) can be useful but it can be suggestive of an atypical follicular tumor. Radiographic features are not useful in making discrimination between a primary thyroid neoplasm and a metastatic thyroid carcinoma. The possibility of a primary thyroid tumor is ruled out by immunohistochemical thyroglobulin staining; in fact thyroglobulin immunohistochemistry is always negative in the foci of metastatic renal carcinoma. The Authors report a case of thyroid metastasis from renal cell carcinoma five years after nephrectomy. Preoperative FNAB suggested a papillary carcinoma. The immunohistochemical staining for thyroglobulin had not been possible. Only the pathological examination of the thyroid tumor could be able to reveal, postoperatively, typical cells with abundant clear cytoplasm and round nuclei and it was possible to make the correct diagnosis of metastasis from renal clear cell carcinoma. Notwithstanding a wrong preoperative diagnosis, surgical management (thyroidectomy) was the treatment of choice.