Sonographic and Clinical Features of Papillary Thyroid Microcarcinoma Less than or Equal to Five Millimeters: A Retrospective Study.

Jacques Emile Dumont,Ruina Zhao,Sheng Cai,Xiaoyan Zhang,Qiong Wu,Yixiu Zhang,Xingjian Lai,Jianchu Li,Xiao Yang,Shenling Zhu,Yuxin Jiang,Bo Zhang

doi:10.1371/journal.pone.0148567

Abstract

ObjectiveTo retrospectively compare the sonographic and clinical features of papillary thyroid microcarcinoma (PTMC) ≤5 mm and PTMC >5 mm to improve the diagnostic value of ultrasonography.MethodsA total of 367 cases of PTMC between January 2013 and December 2014 was included in this study. The patients were classified into group A (≤5 mm, n = 181) or group B (>5 mm, n = 186), and the sonographic and clinical features were reviewed and compared between the two groups.ResultsThere was no significant difference in the shape, ratio of length/width, boundary, peripheral halo ring, echogenicity, cystic change and accompanying Hashimoto's thyroiditis between these two groups. However, the calcification (61.3% vs. 72.6%) and hypervascularity (13.8% vs. 24.7%) were more frequent in group B (p = 0.026 and 0.008, respectively). The patients were younger, and more patients were aged less than 45 years (41.4% vs. 57.0%) in group B. Capsular invasion (7.2% vs. 34.4%), multifocality (21.5% vs. 48.9%), bilaterality (17.1% vs. 39.8%), central lymph node metastasis (13.8% vs. 38.2%) and lateral lymph node metastasis (1.1% vs. 5.4%) were more frequent in group B. No clinical or sonographic feature was related to cervical lymph node metastasis in group A, while less than 45 years in age (p = 0.010), male gender (p = 0.040), capsular invasion (p<0.001), multifocality (p = 0.016) and calcification (p = 0.042) were related to cervical lymph node metastasis in group B.ConclusionsThe sonographic features of PTMC ≤5 mm were similar to those of PTMC >5 mm, including an irregular shape, a length/width ratio of ≥1, an unclear boundary, no peripheral halo ring, hypoechogenicity, no cystic change, calcification, no hypervascularity and no accompanying Hashimoto's thyroiditis. The clinical features of PTMC ≤5 mm were less aggressive than those of PTMC >5 mm.

Highlights

Thyroid microcarcinoma is defined as thyroid carcinoma measuring 10 mm in its greatest dimension [1]
Capsular invasion (7.2% vs. 34.4%), multifocality (21.5% vs. 48.9%), bilaterality (17.1% vs. 39.8%), central lymph node metastasis (13.8% vs. 38.2%) and lateral lymph node metastasis (1.1% vs. 5.4%) were more frequent in group B
No clinical or sonographic feature was related to cervical lymph node metastasis in group A, while less than 45 years in age (p = 0.010), male gender (p = 0.040), capsular invasion (p

Summary

Introduction

Thyroid microcarcinoma is defined as thyroid carcinoma measuring 10 mm in its greatest dimension [1]. Several studies have reported that PTMC is detected in up to 35.6% of autopsy specimens, and up to 37.3% of PTMCs are associated with cervical lymph node metastasis; they exhibit aggressive behavior [2,3,4]. With the development of diagnostic technology, such as high-resolution ultrasonography and fine-needle aspiration biopsy, the diagnosis of PTMC measuring 5 mm in its greatest dimension has increased [5]. In the evaluation and surgical decision of PTMC 5 mm detected by ultrasonography with multifocality, the clinical behavior of PTMC 5 mm is less aggressive than PTMC >5 mm, a higher risk of cervical lymph node metastasis should be considered [5]. The aim of the present study was to retrospectively compare the sonographic and clinical features of PTMC 5 mm and PTMC >5 mm to improve the diagnostic value of ultrasonography

Methods

Results

Conclusion