Intraoperative frozen section can be reduced in thyroid nodules classified as Bethesda categories V and VI

Jing Huang,Pintong Huang,Qin Ye,Kanlun Xu,Yang Sun,Jieli Luo,Chao Zhang,Jianshe Chen

doi:10.1038/s41598-017-05459-x

Jing Huang, Pintong Huang + Show 6 more

Open Access

https://doi.org/10.1038/s41598-017-05459-x

Copy DOI

Abstract

Intraoperative frozen section (FS) can be reduced during thyroid lobectomy according to the results of fine needle aspiration (FNA). We evaluated the role of intraoperative FS in thyroid nodules with different diagnostic categories of the Bethesda System for Reporting Thyroid Cytopathology by FNA. This retrospective study included 1,235 nodules collected via thyroidectomy with both preoperative FNA and intraoperative FS at the Second Affiliated Hospital of Zhejiang University School of Medicine, from January 2011 to January 2014. FNA cytological diagnosis was classified into six categories, based on the Bethesda system. The diagnostic findings of FNA cytology and FS histology were compared with the final histological results. 189 nodules were benign. The remainder were malignant. FS diagnosis was more accurate than FNA diagnosis for nodules classified as Bethesda Categories II, III, and IV (P < 0.05). However, the accuracy of FNA diagnosis in nodules assigned Bethesda Categories V and VI was significantly higher than that of FS (P < 0.05). FS appears be beneficial for thyroid nodules classified as Bethesda categories I through IV. FS may not be necessary in nodules diagnosed as Bethesda Categories V and VI.

Highlights

The incidence of thyroid nodules has increased in recent years[1], with an estimated prevalence of 1–5% for palpable nodules and up to 50% for nonpalpable nodules[2]
Cytological results are classified according to the Bethesda System for Reporting Thyroid Cytopathology[6], which has been applied in our institution since 2011
One hundred and thirty-four (10.85%) nodules were classified as Bethesda Category II, of which 38.06% (51/134) were histologically diagnosed as malignant, 38 were reported as malignant on Frozen section (FS), and 13 were false negatives on intraoperative FS, yielding accuracy rates of 90.30% for FS and 61.94% for fine needle aspiration (FNA)

Summary

Introduction

The incidence of thyroid nodules has increased in recent years[1], with an estimated prevalence of 1–5% for palpable nodules and up to 50% for nonpalpable nodules[2]. Cytological results are classified according to the Bethesda System for Reporting Thyroid Cytopathology[6], which has been applied in our institution since 2011 These cytological diagnoses are determined, as follows: 1) Bethesda I, nondiagnostic or unsatisfactory, 2) Bethesda II, benign, 3) Bethesda III, atypical of indeterminate significance or follicular lesion of indeterminate significance, 4) Bethesda IV, follicular neoplasm or suspicious for a follicular neoplasm, 5) Bethesda V, suspicious for malignancy, and 6) Bethesda VI, malignant. Eighty (6.48%) nodules were reported as Bethesda category I (Table 2), of which 56.25% (45/80) were histologically diagnosed as malignant. One hundred and thirty-four (10.85%) nodules were classified as Bethesda Category II, of which 38.06% (51/134) were histologically diagnosed as malignant, 38 were reported as malignant on FS, and 13 were false negatives on intraoperative FS, yielding accuracy rates of 90.30% for FS and 61.94% for FNA. There was no significant difference in the negative predictive value between FNA and FS (61.94% vs. 86.46%, P > 0.05)

Objectives

Methods

Findings

Conclusion