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Comparison of thyroid fine needle aspiration biopsy results before and after implementation of Bethesda classification
Author(s) -
Ozdemir D.,
Bestepe N.,
Faki S.,
Kilicarslan A.,
Parlak O.,
Ersoy R.,
Cakir B.
Publication year - 2017
Publication title -
cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 48
eISSN - 1365-2303
pISSN - 0956-5507
DOI - 10.1111/cyt.12437
Subject(s) - medicine , bethesda system , malignancy , atypia , thyroid nodules , biopsy , cytology , thyroid , radiology , fine needle aspiration , gynecology , pathology
Objective The Bethesda classification was introduced in 2008 to provide standardisation in the evaluation of thyroid fine needle aspiration cytology ( FNAC ). We compared the diagnostic value of pre‐Bethesda and Bethesda classification systems in the differentiation of benign and malignant thyroid nodules. Methods Medical records of patients who underwent a thyroidectomy between June 2007 and June 2014 were reviewed retrospectively. Nodules evaluated with FNAC before March 2010 were classified as pre‐Bethesda (non‐diagnostic, benign, indeterminate, suspicious for malignancy and malignant), and those evaluated after March 2010 were considered Bethesda (non‐diagnostic, benign, atypia of undetermined significance/follicular lesion of undetermined significance, follicular neoplasia/suspicious for follicular neoplasia, suspicious for malignancy and malignant). Sensitivity, specificity, positive predictive value ( PPV ), negative predictive value ( NPV ) and accuracy of the two classification systems were calculated. Results There were 1810 nodules in the pre‐Bethesda and 5115 nodules in the Bethesda group. The non‐diagnostic rate was significantly higher, and benign and suspicious for malignancy rates were lower in Bethesda compared with the pre‐Bethesda group ( P <.001 for each). When benign cytology was considered negative, and indeterminate, follicular neoplasia/suspicious for follicular neoplasia, suspicious for malignancy and malignant cytologies were considered positive, results for pre‐Bethesda and Bethesda were as follows: sensitivity, 78.9% and 78.5%; specificity, 86.6% and 97.0%; PPV , 42.8% and 72.6%; NPV , 97% and 97.8%; and accuracy, 85.7% and 95.3%, respectively. Conclusions Among operated nodules, percentages of benign and suspicious for malignancy cytologies decreased, and percentages of non‐diagnostic and uncertain cytologies increased with the implementation of Bethesda. The diagnostic value of FNAC seems to have increased with the use of Bethesda classification.