Chang-Joon Ahn

Analysis of Clinicopathologic Features of Papillary Thyroid Microcarcinoma According to Cut-off of Tumor Size

Purpose: Although the detected incidence of papillary thyroid microcarcinoma (PTMC) has increased with development of ultrasonography and fine-needle aspiration biopsy, the best treatment has not yet been established. Treatment decisions require information on many factors including lymph node metastasis, extrathyroidal extension, and bilaterality. With this aim, the present study analyzed clinicopathologic features of PTMC according to cut-off of tumor size. Methods: The clinicopathologic features of patients with PTMC between January 2007 and December 2009 were reviewed retrospectively from medical records. Patients were divided according to tumors lesser than or equal to cut-off (Group I) and tumors exceeding cut-off (Group II). Results: Both capsule invasion and lymphovascular invasion were significantly different at all cut-off diameters (5 ∼9 mm). Central node metastasis revealed a difference in all cut-off values except 8 mm. Extrathyroidal extension differed at all cut-off values except 5 mm. Bilaterality displayed a statistically significantdifference only at the 8 mm cut-off. Conclusion: A cut-off of 5 mm represents a safe value to discriminate less aggressive from aggressive treatment for PTMC. (Korean J Endocrine Surg 2010;10:152-156)