AUTHOR=Lee Yoo Jin , Kim Dong Wook , Shin Gi Won , Park Jin Young , Choo Hye Jung , Park Ha Kyoung , Ha Tae Kwun , Kim Do Hun , Jung Soo Jin , Park Ji Sun , Moon Sung Ho , Ahn Ki Jung , Baek Hye Jin 

TITLE=Comparison of Ultrasonography Features and K-TIRADS for Isthmic and Lobar Papillary Thyroid Carcinomas: A Single-Center Study

JOURNAL=Frontiers in Endocrinology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2020.00328

DOI=10.3389/fendo.2020.00328

ISSN=1664-2392

ABSTRACT=<p><bold>Objective:</bold> This study aimed to compare ultrasonography (US) features and the Korean-Thyroid Imaging Reporting and Data System (K-TIRADS) categories for diagnosing isthmic and lobar papillary thyroid carcinomas (PTC).</p><p><bold>Methods:</bold> From January 2009 to December 2012, 163 patients who underwent thyroid surgery and were confirmed with a post-operative histopathological diagnosis of isthmic PTC were retrospectively included. Fifty-nine patients were excluded because their tumor size was &lt;0.5 cm or because of other reasons. The control group comprised of 145 patients who underwent thyroid surgery from January to April 2013 for a classic type of PTC, with the largest diameter being ≥ 0.5 cm and located in the thyroid lobe. A single radiologist retrospectively reviewed the US features and K-TIRADS categories of each nodule using a picture archiving and communication system.</p><p><bold>Results:</bold> Among 104 patients with isthmic PTC, 95 and 9 had primary and secondary cancers, respectively. On the other hand, all 145 patients with lobar PTC had primary cancers. Isthmic PTC showed a lower prevalence of non-parallel orientation than lobar PTC (23.1 and 71%). Nodule orientation was the only US feature statistically different between the two groups (<italic>p</italic> &lt; 0.0001). However, there was no significant difference in patient age, sex, nodule size, composition, echogenicity, microcalcification, spiculated/microlobulated margin, and K-TIRADS category between the two groups (<italic>p</italic> &gt; 0.05).</p><p><bold>Conclusions:</bold> K-TIRADS may be useful in the diagnosis of both isthmic and lobar PTC.</p>