Abstract :
Introduction: The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is a six category
scheme for reporting thyroid Fine Needle Aspirates (FNAs) and represents a major step towards a
uniform reporting system for thyroid FNAs, enabling better understanding of thyroid cytopathology
report by referring clinicians and providing rational management guidelines. The present study was
carried out to analyse cytological features of thyroid FNAs and categorise them by The Bethesda System
for Reporting Thyroid Cytopathology; and to assess interobserver variability between two independent
reporting pathologists using the Bethesda system.
Materials and Methods: The study was conducted over three years from Nov. 2015 to Oct. 2018
in the Department of Pathology, Government Medical College, Jammu. The thyroid FNAs were
categorized according to the Bethesda system by two independent pathologists in a double blinded
fashion. Interobserver variability was assessed by calculating percentage of agreement, disagreement and
statistically using Cohen’s kappa.
Results: A total of 610 cases were categorized as Nondiagnostic-51 cases (8.36%), 50 cases (8.20%);
Benign-524 cases (85.90%), 510 cases (83.61%); Atypia of Undetermined Significance-2 cases (0.33%),
12 cases(1.97%); Follicular Neoplasm-15 cases (2.46%), 16 cases (2.62%); Suspicious for Malignancy-
1 case (0.16%), 6 cases (0.98%); Malignant-17 cases (2.79%), 16 cases (2.62%) by two pathologists
respectively. The two pathologists agreed in 548 cases (89.84%) and disagreed in 62 cases (10.16%)
with Cohen’s kappa=0.628 (62.8%). Agreement was highest in Benign category-95.68%, followed by
Malignant-87.5%, Follicular Neoplasm -75%, Nondiagnostic-68%. No agreement was seen in Atypia of
Undetermined Significance and Suspicious for Malignancy categories.
Conclusion: The present study thus encourages the use of The Bethesda System for Reporting Thyroid
Cytopathology as a standardized reporting system with relative ease of reproducibility for effective
communication among pathologists and clinicians with regard to thyroid Fine Needle Aspiration Cytology
reporting and management.
Keyword :
Bethesda system, Thyroid fine needle aspiration, Cytology, Interobserver variability.