A Rare Case of Metastasis of Renal Clear Cell Carcinoma to the Thyroid Gland 3 Years after Nephrectomy in A 65 Years Old Man

Introduction: thyroid gland metastatic tumors are rare in clinical practice. Clear cell RCC is one of common metastatic tumors to thyroid. this variant has tendency to metastasize widely, even before local symptoms. We report a case of clear cell renal carcinoma metastasis to thyroid gland 3 years after nephrectomy that incidentally found after thyroidectomy was done for patient because of thyroid enlargement in background of multinodular goiter.Case presentation: A 65-year-old Iranian man with a history of multinodular goiter and thyroid enlargement referred to surgeon for thyroidectomy because of compressive effect on the adjacent trachea. Patient had history of nephrectomy due to clear cell RCC 3 years’ ago. after thyroidectomy gross and histological examination of thyroid revealed clear cell renal carcinoma metastasis to thyroid gland in background of multinodular goiter. The diagnosis was confirmed by immunohistochemistry staining. IHC staining of tumor cells were positive for CD10 and Vimentin and negative for CK7, CK20 and TTF-1 markers.Conclusions: patients with multinodular goiter and thyroiditis are more prone to metastasis to thyroid gland if they have history of malignancy especially renal cell carcinoma. Examination and radiological evaluation of thyroid even many years after nephrectomy is mandatory in such cases to find metastatic nodules as soon as possible. FNA biopsy is also a good diagnostic procedure in these patients because of low morbidity and cost if a nodule is clinically suspicious for metastasis.

کلیدواژه ها:

renal cell carcinoma ، thyroid gland ، metastasis ، multinodular goiter