Metastatic thyroid tumor cases due to renal cell carcinoma

Abstract

The incidence of metastatic thyroid tumors is rare because of the high oxygen and high iodine en­vi­ron­ment in the thyroid gland. In addition, since the thyroid gland has a rich blood flow, cancer cells hardly ad­here to it. This report describes a case of thyroid tumor metastasized from renal cell carcinoma, combined with a clinical review.
A 55-year-old woman had noticed neck swelling 3 to 4 years ago which had been observed as a benign thyroid tumor. The mass lesion increased gradually in size and fine-needle aspiration findings suggested follicular tumor. The patient had a history of renal cell carcinoma 11 years ago and a recurrence in the pancreas 9 years ago. The right lobe was diffusely enlarged and the border was unclear in ul­tra­so­nog­ra­phic findings. CT and MRI examinations showed the tumor with high contrast effect. There was no ob­vi­ous lymph node metastasis or distant metastasis. Right lobectomy was performed and the bleeding volume was about 280 ml during surgery. Pathological examination after surgery confirmed metastasis of renal cell carcinoma. Lung metastasis appeared 21 months after thyroid surgery and additional treatment for lung metastasis is now under way, but there is no recurrence in the head and neck.