Diagnostic accuracy of Fine Needle Aspiration Cytology of thyroid lesions along with histopathological correlation. A 3-year retrospective study

Abstract

Background: Among endocrine malignancies, thyroid carcinoma is by far the most frequent. Approximately 5 to 15 percent of all thyroid nodules have been found to be cancerous in recent years. The results of a cytology test can help doctors determine the best course of therapy for their patients, including surgery. There has been a great deal of research into the accuracy of FNAC in diagnosing thyroid cancer.

Objectives: Diagnose thyroid FNAC lesions according to the Bethesda approach and compare them with histological diagnoses to establish diagnostic value and accuracy.

Materials and Methods: This is a three-year retrospective research conducted at the King Khalid Hospital in Najran. Data including demographics, FNAC report and histopathological diagnosis was collected from the hospital records. Thyroid cytology was classified into six categories based on the Bethesda system and histopathological correlation was done. Calculations were performed to determine the diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value.

Results: The average age was 36.6 ±11.9 years, ranging from 16 to 83 years.. Females made up 91.5 percent of the sample, having a male-female ratio of 1:10. There were 24 (29.3%) Bethesda category II lesions, 28 (34.14%) Bethesda category IV lesions, and the least 2 Bethesda category III lesions (2.4 percent ). On FNAC, 12 (14.63 %) of the lesions were malignant. There was a 92.4 percent sensitivity, 68.9 percent specificity, 84.5% positive predictive value (PPV), 83.3% negative predictive value (NPV), and an accuracy of 84.1 percent for FNAC validity.

Conclusion: This study found that in FNAC thyroid the sensitivity and specificity are both satisfactory and our findings are comparable. The Bethesda Tiered Diagnostic System is a great tool for diagnosing and managing thyroid lesions. Cytopathologists should be mindful of potential diagnostic pitfalls, which can be minimized even more if aspirates are acquired under USG supervision.