Clinical Behaviors and Treatment Outcome of Papillary Thyroid Microcarcinomas：Tumor Size-Based Therapeutic Concept

Korean Journal of Head & Neck Oncology 2008;24(1):47-52.
Published online May 30, 2008.

Jandee Lee;Dong-Kyu oh;Seung Soo Lim;Kee-Hyun Nam;Woong Youn Chung;Euy Yong Soh;Cheong Soo Park

미세 유두 갑상선암의 크기에 따른 임상상 및 단기간 치료 결과

이잔디;오동규;임승수;남기현;정웅윤;소의영;박정수

Abstract

Purpose
：The incidence of papillary thyroid microcarcinoma(PTMC) has increased due to the widespread use of high resolution ultrasonography and fine-needle aspiration biopsy. However, the clinical and biologic behaviors of PTMC is debatable. The aim of this study was to describe clinicopathologic features of PTMC and to suggest whether tumor size(5mm) might prove the useful parameter for determining the surgical strat-egy in PTMC. Material and Methods ：From Jan. 2000 to Dec. 2005, 1355 of 2678 patients with papillary thyroid car-cinoma were identified as having PTMC, based on tumor size≤10mm(50.6%). Among patients with PTMC, we further separated tumors<5mm(minute group：group M) from those 5 to 10mm(tiny group：group T). We compared the clinicopathological characteristics and the TNM stagings between two groups.
Results
：There were 114(8.4%) men and 1241(91.6%) women with a median age of 47 years(range；13-79). During a mean follow-up of 47.3(range；22-93), 13 patients(1.0%) developed locoregional recur-rences and 3 patients(0.2%) showed distant metastases at initial presentation. Statistical analysis revealed that the presence of extracapsular invasion(p<0.0001), invasion to adjacent structure(p<0.0001), multifocality(p< 0.0001), central lymph node metastasis(p<0.0001), and lateral lymph node metastasis(p<0.0001) were all significantly higher in tiny group(tumor≥5mm). Furthermore, minute group demonstrated a significantly lower tumor stage(AJCC TNM classification) compared with tiny group(p<0.0001).
Conclusion
：Patients with PTMC have a favorable treatment outcomes, although the distinction needs to be made with reference to the clinicopathologic behaviors. It would be reasonable to consider that tumor size(5mm) would be useful parameter for the treatment strategy of PTMC.

Key Words: Papillary thyroid microcarcinoma, Clinical behaviors, Minute carcinoma, Tiny carcinoma, Treatment outcome