Papillary microcarcinoma of the thyroid gland is defined as a tumor of 1.0 cm or less in diameter according to the WHO. Long-term follow-up of patients with papillary tumors of small size has shown that the prognosis is very good in spite of their ability to metastasize to regional lymph node and distant site, but the surgical management of them are still unclear. The aim of this study is to analyze the clinical and pathologic features and to determine the adequate extent of surgery of papillary microcarcinomas.

189 patients with papillary carcinoma of 1 cm or less in diameter underwent thyroidectomy at center between 1994 to 2001. Their medical records were reviewed retrospectively. Chi-square test was used for statistical analysis.

26.3% of 720 papillary carcinomas were microcarcinomas and 44.4% of patients with these tumors were presented for palpable neck mass. 73.6% of 189cases were diagnosed preoperatively as papillary carcinoma by FNAC and their mean size was 6.1 mm. Only 22 patients underwent lobectomy and the others did subtotal or total thyroidectomy with/without modified radical neck dissection. Among 5 recurred cases, 3 recurred in contralateral lobe after lobectomy and 2 in cervical lymph node after subtotal or total thyroidectomy. Smaller tumors had a lower rate of extra- thyroidal extension but the same rate of lymph node metastasis as larger tumors.

Detection by screening ultrasonography and the proportion of microcarcinoma in papillary carcinoma are increasing and more than subtotal thyroidectomy is recommended for papillary microcarcinoma due to its multifocality and remnant recurrence.