Incidental multifocal papillary microcarcinomas of the thyroid: Is subtotal thyroidectomy combined with radioiodine ablation enough?

Background The extent of thyroid resection and the necessity of lymph node dissection has become an issue of controversy in patients with incidental multifocal papillary microcarcinoma. Method Between 1993 and 2001 a total of 4120 patients underwent surgery for thyroid diseases: 142 patients showed papillary thyroid cancer of less than or equal to 1 cm, multifocal microcarcinomas were found in 22 patients (15.5%). Twenty patients (17 women, three men, aged 26-71 years) met the inclusion criterion of having pre- and intraoperatively no indication of malignancy (incidentaloma). A limited surgical procedure ranging from bilateral subtotal (n=15), ipsilateral total, contralateral subtotal (n=4) to bilateral total (n=1) thyroidectomy without lymph node dissection was performed. The mean volume of thyroid remnants was 4.3 ml. Results In 16/20 (80%) patients, the thyroid remnant was ablated by the first dose of I-131, using 3.7 GBq I-131 in 15 patients and 1.85 GBq I-131 in one patient. Three patients received a second, and one patient a third radioiodine ablation. All 20 patients remained free from relapse or metastasis, documented by negative I-131 whole-body scintigraphy and unmeasurable thyroglobulin levels after thyroid hormone with drawal in hypothyroidism. One patient died 7 years after the diagnosis of thyroid cancer from primary lung cancer. Median follow-up was 65 months (range, 24-120 months). Conclusion Subtotal thyroidectomy followed by radioiodine therapy without completion thyroidectomy and lymphadenectomy is a possible option in incidental multifocal microcarcinomas. (C) 2005 Lippincott Williams Wilkins.