A Case of Renal Cell Carcinoma with Thyroid Metastasis / 대한내분비학회지

ABSTRACT

Metastatic thyroid cancer is uncommon but must be distinguished from primary thyroid cancer because of the differences in management and prognosis. Although renal cell carcinoma is one of the most common tumors that metastasize to the thyroid gland, such a case has never been reported in Korea. We describe the first case of metastatic renal cell carcinoma in the thyroid gland. A 66-year-old man presented with a neck mass detected about 6 weeks previously. He had undergone left nephrectomy due to renal cell carcinoma 8 years before and had remained disease-free thereafter. Computed tomography of the neck showed a 5 cm-sized thyroid mass. Fine needle aspiration cytology revealed some malignant cells containing intranuclear inclusions which were assumed to be papillary thyroid carcinoma. The patient underwent total thyroidectomy. Histologic diagnosis of the thyroid mass was metastatic renal cell carcinoma and further evaluation with chest computed tomography showed two enlarged mediastinal lymph nodes suggesting metastases. The previous history of malignancy should be scrutinized when managing a thyroid mass in patients with a prior or concomitant malignancy, and the possibility of metastasis should be carefully considered.