Comparison of Fine Needle Aspiration Cytology in Thyroid Lesions using The Bethesda System for Reporting Thyroid Cytopathology with Ultrasonography using Thyroid Imaging Reporting and Data System

Archana Tiwari,Rupesh Sharma,Sudeep Regmi

doi:10.22502/jlmc.v6i2.274

Abstract

Introduction: Thyroid nodule is a common presentation. The estimated prevalence of thyroid nodules is 4-7% by clinical examination and 50-60% on ultrasonographic (USG) evaluation. Most are benign without any symptoms or cosmetic concerns. Only around 5% are found to be malignant. Methods: This prospective study evaluated a total of 54 patients with thyroid lesions presenting to Otorhinolaryngology, Surgery and Internal Medicine out-patient departments of a tertiary hospital for a period of nine months. The thyroid lesions were categorized into different categories using Thyroid Imaging Reporting and Data System (TIRADS) by USG and The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) by fine needle aspiration (FNA). The agreement between TIRADS and TBSRTC was evaluated using Cohen's kappa statistics. Results: By FNA, 68.5% were benign lesions whereas 7.4% were malignant. Follicular Neoplasm (FN) or Suspicious for FN and Suspicious for Malignancy category comprised 5.6% each. 1.9% of the lesions showed Atypia of Unknown Significance (AUS). 11.1% of the lesions were non-diagnostic or unsatisfactory for evaluation. Overall agreement between the cases by USG and FNA using the TIRADS and TBSRTC respectively was 77.77%. There was a substantial agreement between the diagnosis made by these systems, kappa (κ)= .633 (95% CI, 0.41 to 0.85, p<0.05). Conclusion: This study observed a substantial agreement between the diagnosis made by TIRADS on USG and TBSRTC on FNA. Our study advocates the stratification of thyroid lesions according to TIRADS so that only suspicious lesions undergo FNA.

Highlights

This study attempts to observe the concordance between the Thyroid Imaging Reporting and Data System (TIRADS) and The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) on thyroid lesions of patients presenting to our hospital
For the purpose of statistical analysis, category I was omitted from both TIRADS and TBSRTC, and cases of TBSRTC VI category were retained in the TBSRTC V as there is no corresponding category i.e. TIRADS VI
The malignant lesions (TBSRTC-VI) comprised 7.4% cases. These cases were revised as TBSRTC-V for statistical purpose, as TIRADS has no corresponding category and TIRADS-V shows the highest risk of malignancy by USG

Summary

INTRODUCTION

Regmi S. et al Comparison of Fine Needle Aspiration Cytology in Thyroid Lesions [3,4,5] The six diagnostic categories suggested by TBSRTC are: I) Non-diagnostic or unsatisfactory; II) Benign; III) Atypia of Undetermined Significance (AUS) or Follicular Lesion of Undetermined Significance (FLUS); IV) Follicular Neoplasm (FN) or Suspicious for Follicular Neoplasm; V) Suspicious for Malignancy; VI) Malignant.[5]. The Thyroid Imaging Reporting and Data System (TIRADS), first proposed by Horvath et al.[7] was established to standardize the scoring system of thyroid USG and provide recommendations for using FNA and to improve appropriate patient management.[4,8,9] The TIRADS categories as suggested by American College of Radiology (ACR) and known as ACR TI-RADS are: I) Benign; II) Not Suspicious; III) Mildly Suspicious; IV) Moderately Suspicious; V) Highly Suspicious.[4]. This study attempts to observe the concordance between the TIRADS and TBSRTC on thyroid lesions of patients presenting to our hospital

METHODS

RESULTS

DISCUSSION

CONCLUSION