Clinically Significant, Isolated Metastatic Disease to the Thyroid Gland

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= 5), esophageal adenocarcinoma (n= 1), pulmonary squamous cell carcinoma (n= 1), gastric leiomyosarcoma (n= 1), lingual squamous cell carcinoma (n= 1), and parotid gland carcinoma (n= 1). Three patients underwent preoperative fine-needle aspiration (FNA), all of which were suggestive of metastatic disease. The mean time from resection of the primary tumor to thyroid metastases was 3.5 ± 6.0 years (range 0–19.5 years). Total thyroidectomy (n= 5) or lobectomy (n= 5) was performed without morbidity or mortality. After a median follow-up of 5.2 years six patients are alive and two are free of disease. Moreover, no patients have had recurrent disease in the neck. Thus carcinomas metastatic to the thyroid represent a rare cause of clinically significant thyroid disease, with RCCs comprising 50%. Most thyroid metastases (80%) present within 3 years of primary tumor resection, but with RCC they can occur as late as 19 years. The diagnosis of metastatic disease should be suspected in patients with even a remote history of cancer, especially RCC, and an FNA revealing clear cell or spindle cell carcinoma. Contrary to previous reports, long-term survival can be achieved after resection of the metastatic tumor. Furthermore, thyroidectomy may also palliate/prevent the potential morbidity of tumor recurrence in the neck.