ORIGINAL ARTICLE
Evaluation of Concordance of Ultrasound, Cytology,
and Histopathology in Solitary Thyroid Nodules
Yashwant Singh Rathore
1
, Gopal Puri
2
, Sushma Yadav
3
, Shipra Agarwal
4
, Surabhi Vyas
5
, Kamal Kataria
6
, Sunil Chumber
7
,
Kanika Sharma
8
, Amit Padar
9
Received on: 12 April 2023; Accepted on: 04 May 2023; Published on: 30 June 2023
A BSTRACT
Introduction: The American College of Radiology (ACR)-Thyroid Imaging and Reporting Data System (TIRADS) is used to classify the ultrasound
(USG) findings and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is used to classify the fine needle aspiration (FNAC)
findings for a solitary thyroid nodule (STN).
Objective: The objective of this study is to assess the concordance between TIRADS and TBSRTC with final postoperative histopathology in
cases of STN and to calculate the risk of malignancy (ROM).
Materials and methods: The prospective observational study was conducted at a tertiary care hospital in India. Patients underwent USG and
FNAC before undergoing surgery. Final concordance was analyzed with histopathology examination.
Results: The study included 80 subjects. The ROM for the TIRADS categories was 25.92%, 65.21%, and 100% for TIRADS (TR)3, TR4, and TR5
nodules, respectively. The ROM for Bethesda categories was 0% for Bethesda (B) I (BI), 6.5% for BII, 47.36% for BIII, 46.67% for BIV, and 100% for
BV and BVI. Concordance was calculated using the kappa index, which was 0.21 with SE = 0.08 and 95% confidence interval (CI) = 0.061–0.359.
After broad categorization, the re-calculated kappa was 0.38 with SE = 0.09 (95% CI: 0.203–0.564) with the observed agreement of 64% and
by chance agreement of 41.6%.
Conclusion: There is fair concordance between ACR-TIRADS and TBSRTC. Indeterminate concordant and discordant nodules mandate a closer
look owing to the high ROM.
Keywords: Bethesda, Concordance, Risk of malignancy, Solitary thyroid nodule, Thyroid Imaging and Reporting Data System.
Indian Journal of Endocrine Surgery and Research (2023): 10.5005/jp-journals-10088-11204
I NTRODUCTION
The disorders of the thyroid gland are the second most common
endocrine dysfunction in the world after diabetes. They present
commonly to an endocrine surgeon with a thyroid swelling.
The prevalence of these swellings is dependent on the method
of identification. The estimated prevalence by palpation alone
ranges from 4 to 7%
1
compared to the ultrasound (USG) detection
rate of 20–76% in adult population.
2,3
The gold standard test for
the identification of nodules is the high-resolution USG.
4
A single
USG feature in isolation is not capable of predicting malignancy
in these nodules.
5
Therefore, in order to permit USG imaging for
the identification and stratification of nodules in terms of risk of
malignancy (ROM), several guidelines have been developed. The
American College of Radiology (ACR)-Thyroid Imaging and Reporting
Data System (TIRADS) is developed and validated based on existing
multi-institutional data and expert opinion.
6
In this system, each of
six characteristics of thyroid nodule are evaluated and individual
score is given to each category. The sum of individual scores
gives the total score. The total score is then used to stratify the
nodule into five categories equivalent to normal, benign, probably
benign, suspicious, and malignant. Higher the score, more is
ROM. Cytological evaluation of thyroid swellings is a rapid, easy,
and inexpensive diagnostic procedure. But in view of the lack of
uniformity in the reporting systems used across the world and to
improve pathologist–clinician communication, The Bethesda System
for Reporting Thyroid Cytopathology (TBSRTC) was introduced in
2007 and subsequently revised in 2017.
7,8
The TBSRTC classifies all
thyroid aspirates into six categories, with each category having an
associated ROM and guidelines for management.
Mere diagnosis of thyroid nodule causes anxiety to the patient
and the desire to know the ROM in nodule and further management
plan. If we can confidently make preoperative diagnosis of benign
or malignant nodule, this will help in putting the brakes on
unnecessary thyroidectomies in benign asymptomatic thyroid
nodules and simultaneously not leaving behind the malignancy.
There are various studies validating the TIRADS
9–11
and TBSRTC
systems
2,12,13
individually demonstrating very good sensitivity
and good specificity. Most of studies utilize fine needle aspiration
(FNAC) diagnosis to validate USG results but FNAC is not a gold
standard.
11,14
Very few such studies in Indian population are
available. Only a handful of authors have evaluated concordance of
© The Author(s). 2023 Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.
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1–3,6–9
Department of Surgical Disciplines, AIIMS, New Delhi, India
4
Department of Pathology, AIIMS, New Delhi, India
5
Department of Radiodiagnosis, AIIMS, New Delhi, India
Corresponding Author: Yashwant Singh Rathore, Department of
Surgical Disciplines, AIIMS, New Delhi, India, Phone: +91 9911337726,
e-mail: dryashvant.r@gmail.com
How to cite this article: Rathore YS, Puri G, Yadav S, et al. Evaluation of
Concordance of Ultrasound, Cytology, and Histopathology in Solitary
Thyroid Nodules. Indian J Endoc Surg Res 2023;18(1):17–23.
Source of support: Nil
Conflict of interest: None