Surgical treatment of intrathyroid metastases: Preliminary results of a multicentric study

Background: Intrathyroid metastases (ITM) are rare and usually have a dismal prognosis. The aim of this study was to detect which neoplasms metastasize most often to the thyroid gland, their clinical features and treatment options. Materials and Methods: Retrospective analysis of clinical files of 17,122 patients submitted to surgery for thyroid disease between 1995 and 2005. Twenty-five patients (median age 61 years) were affected by ITM. Results: The site of the primary tumor was: kidney (15), lung (4), colon (3), breast (1), melanoma (1), and unknown in 1 patient. Ten patients (40% ) complained of preoperative symptoms, in the others, thyroid involvement was incidentally discovered during the follow-up for the primary cancer. Twenty patients (80%) underwent total thyroidectomy, 3 received thyroid lobectomy and 2 palliative procedures. Morbidity was 16%, mortality was nil. The median follow-up was 24 months. Conclusion: TTM should always be suspected in any patient with a previous history of malignancy. Fine-needle agobiopsy (FNAB) with immunohistochemical stains may help in preoperative workup. A long delay between the primary tumor and the recurrence warrants surgery and total thyroidectomy seems to be the treatment of choice because of the multifocality of metastasis to the thyroid gland.