Significance of distance between tumor and thyroid capsule as an indicator for central lymph node metastasis in clinically node negative papillary thyroid carcinoma patients.

Chan Yong Seong,Sang Mok Lee,June Young Choi,Sun-Won Park,Su-Jin Kim,Ka Hee Yi,Kyu Eun Lee,Ki-Tae Hwang,Young Jun Chai,Jumana Yousuf Al-Aama

doi:10.1371/journal.pone.0200166

Abstract

The aim of this study was to evaluate preoperatively identifiable clinical and ultrasonographic characteristics associated with central lymph node metastasis (CLNM) in clinically node negative papillary thyroid carcinoma (PTC) patients. Records of the patients who underwent thyroidectomy with prophylactic central lymph node dissection due to clinically node negative PTC (size, 1.0–3.0 cm) were reviewed. Of a total of 174 patients, 71 (40.8%) had CLNMs. CLNM was more associated with capsule invasion than capsule non-invasion on ultrasonography (68.4% vs. 37.4%, p = 0.009). In the 155 patients without capsule invasion, a distance from the capsule < 1.9 mm was associated with CLNM in univariable (p = 0.002) and multivariable analysis (p < 0.001). Any PTC patient with a distance from the capsule ≥ 1.9 mm did not have CLNM whereas 40.8% (58/142) of PTC patients with a distance from the capsule < 1.9 mm had CLNM. CLNM was not associated with age, gender, or tumor size on ultrasonography. Distance from capsule ≥ 1.9 mm on preoperative ultrasonography was a significant indicator for not having CLNM in clinically node negative PTC patients. Measuring distance from the capsule on preoperative ultrasonography images could help select patients with PTC who could benefit from prophylactic central lymph node dissection.

Highlights

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy worldwide, and its prognosis is usually favorable
We investigated whether central lymph node metastases (CLNM) in cN0 PTC patients can be predicted by using preoperatively identifiable clinical and ultrasonographic features, including age, gender, tumor size, and the distance between the tumor and thyroid capsule
Consecutive patients with solitary PTC who underwent thyroidectomy combined with elective prophylactic central lymph node dissection at Seoul National University Boramae Medical Center from January 2010 to December 2016 were eligible for this study

Summary

Introduction

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy worldwide, and its prognosis is usually favorable. CLNM in these cN0 patients is common, ranging from 52 to 64% [7, 8] In this regard, previous studies have attempted to predict CLNM by evaluating clinicopathological characteristics, rather than by detecting CLNM itself [5, 9, 10]. Previous studies have attempted to predict CLNM by evaluating clinicopathological characteristics, rather than by detecting CLNM itself [5, 9, 10] Such risk factors for CLNM, which include extrathyroidal extension, multifocality, lymphovascular invasion, and genetic mutations, cannot be predicted preoperatively and are of little use in determining surgical extent

Objectives

Methods

Conclusion