Accuracy of thyroid fine needle aspiration cytology by using bethesda system : a hospital based study

Rasi, Raja Zubaidah Raja Mohd (2017) Accuracy of thyroid fine needle aspiration cytology by using bethesda system : a hospital based study. Masters thesis, Universiti Sains Malaysia.

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Aim: In Hospital University Science of Malaysia, The Bethesda System of Reporting Thyroid Cytology (TBSRTC) was not widely used by pathologist or surgeon/clinician. Instead, conventional reporting system was used and the result was not given tiered classification as in TBSRTC. This study is a retrospective study to review all thyroid FNACs with histopathological correlation in 5 years (2010 to 2014) base on Bethesda System and to look for the accuracy as well as sensitivity and specificity. Methods: We identified total of 563 thyroid FNACs cases performed from January 2010 till December 2014 in Hospital Universiti Sains Malaysia (HUSM), a teaching hospital in Kelantan, which form our study population. All cases were identified from the database of Laboratory Information System (LIS) in the Department Pathology, HUSM. After excluding the cases with exclusion criteria, total of 110 FNAC cases were included in this study. These cases were thyroid FNAC with good quality of slides and with histopathology examination (HPE) result. Primary investigator, a pathologist and a cytopathologist reviewed all slides from 110 cases and consensus diagnosis was given using TBSRTC. SPSS version 20.0 is used for data entry and analysis. Descriptive statistic is used for socio demographic data. Stata software is used for p-value by usingFisher Exact test for objective number 2. Statistic formulas are used to calculate the accuracy, sensitivity and specificity. Results:The patients age were range from 11 to 80 years. The mean age of the patient included in this study was 44.70+/-14.52 (mean+/-SD) years. There were 94 or 85.5% female and 16 or 14.5% male patients. Among 110 cases which were reviewed using TBRSTC, 78 cases or 70.9% were reported as benign on cytology, 1 case or 0.9% was reported as Atypia of Undetermined Significant (AUS), 9 cases or 8.2% were reported as follicular neoplasm, 9 cases or 8.2% were reported as suspicious of malignancy and 13 cases or 11.8% were reported as malignancy. Cyto-histopathological correlation shows 29 cases or 26.4% were true positive, 75 cases or 68.2% were true negative, 3 cases or 2.7% were false positive and 3 cases or 2.7% were false negative. Histopathological examination shows, 25 cases or 22.7% were malignant and 85 cases or 77.3% were benign. Among female patients, 76 cases or 81% were benign and 18 cases or 19% were malignant histologically. Whereas, among male patients, 7 cases or 44% were benign and 9 cases or 56% were malignant histologically. 18 cases or 66.7% of malignant cases were female and 9 cases or 33.3% of malignant cases were male. 76 cases or 91.6% of benign cases were female and 7 cases or 8.4% of benign cases were male. Cyto-histopathological correlation shows 96.2% benign and 3.8% malignant in Bethesda II (benign), 100% malignant in Bethesda III (Atypia of Undetermined Significant/Follicular Lesion of Undetermined Significant), 55.6% benign and 44.4% malignant in Bethesda IV (follicular neoplasm), 33.3% benign and 66.7% malignant in Bethesda V (suspicious malignancy) and 100%malignant in Bethesda VI (malignant). Statistically, the overall accuracy of thyroid FNAC by using Bethesda System is 94.5%, the sensitivity is 90.6% and the specificity is 96.1%. The positive predictive value is 90.6% and the negative predictive value is 96.1%. By looking at each categories, benign (category II) had 96% accuracy, AUS (category III) had 100% accuracy, follicular neoplasm (category IV) had 100% accuracy, suspicious of malignancy (category V) had 66% accuracy and malignancy (category VI) had 100% accuracy. Conclusion: From this study, we conclude that FNA is the most accurate and cost effective method for evaluating thyroid nodule. This study also concludes that The Bethesda System of Reporting Thyroid Cytology have high accuracy, sensitivity and specificity. This system also can increase the accuracy in malignant category.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Biopsy, Fine-Needle
Subjects: R Medicine
Divisions: Kampus Kesihatan (Health Campus) > Pusat Pengajian Sains Perubatan (School of Medical Sciences) > Thesis
Depositing User: Mr Abdul Hadi Mohammad
Date Deposited: 12 Jun 2019 08:44
Last Modified: 22 Oct 2020 03:03

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