Abstract :
Introduction: Fine Needle Aspiration Cytology (FNAC) is the first line diagnostic procedure for evaluating
thyroid lesions. The present study was carried out to assess the diagnostic utility of thyroid FNAC using
The Bethesda System for Reporting Thyroid Cytopathology.
Materials and Methods: It was a one year prospective study conducted in the Department of Pathology,
Government Medical College, Jammu and included all patients presenting with thyroid swelling referred
to this department. The thyroid fine needle aspirates from these patients were classified into six categories
according to The Bethesda System for Reporting Thyroid Cytopathology. The Risk of Malignancy was
calculated for each Bethesda category by follow-up histopathology. Sensitivity, Specificity, Positive
Predictive Value (PPV) and Negative Predictive Value (NPV) were also calculated using histopathology
diagnosis as gold standard.
Results: Thyroid fine needle aspirates from a total of 300 patients were classified according
to Bethesda system as Nondiagnostic (ND)- 17cases(5.67%), Benign- 264cases(88%), Atypia of
Undetermined Significance (AUS)- 1case(0.33%), Follicular Neoplasm(FN)-6cases(2%), Suspicious for
malignancy(SFM)- 0case( 0%) and Malignant- 12cases(4%). The Risk of Malignancy was Nondiagnostic-
50%, Benign-0%, AUS-0%, FN-50%, Suspicious for malignancy-not possible, Malignant-100%.
Sensitivity, Specificity, PPV and NPV were 100%, 100%, 100%, 100% (FN excluded); 80%, 100%, 100%,
96% (FN included as benign); and 100%, 95.83%, 83.33%, 100% (FN included as malignant).
Conclusion: The present study concludes Bethesda system to be an effective reporting system for
thyroid cytology, FNAC to be a sensitive and specific test for evaluation of thyroid lesions and FNAC
using Bethesda guidelines is useful in risk assessment of thyroid nodules thereby guiding appropriate
management.
Keyword :
Thyroid fine needle aspiration cytology, Bethesda system, Risk of malignancy, Sensitivity, Specificity.