[Fine needle aspiration cytology of thyroid nodules: a cytopathologic study of 2 043 cases].

OBJECTIVE: To evaluate the clinical value of thyroid fine needle aspiration cytology(FNAC) and the Bethesda system for reporting thyroid cytopathology(TBSRTC). METHODS: FNAC was performed for 2 043 cases and cytopathological data were retrospectively analyzed. Cytopathological diagnoses according to TBSRTC were classified as non-diagnostic, benign, atypia of undetermined significance/follicular lesion of undetermined significance(AUS/FLUS), follicular neoplasm/suspicious for follicular neoplasm(FN/SFN), suspicious for malignancy(SM) and malignancy. The results of 234 FNAC samples in which surgery was performed were compared with the histological diagnoses. RESULTS: Of the 2 043 FNAC samples, 15.7%(320/2 043)were non-diagnostic, 51.2%(1 047/2 043)were benign, 16.6%(339/2 043) were AUS/FLUS, 2.3%(46/2 043)were FN/SFN, 8.6%(176/2 043)were SM and 5.6%(115/2 043)were malignant. In 234 cases, there was follow-up histology. Rates of malignancy were as follows: non-diagnostic, 18.2%(2/11); benign(2.2%, 1/45); AUS/FLUS(25.6%, 10/29); FN/SFN(12.1%, 10/39); SM(91.8%, 56/61); malignant(100.0%, 45/45). The sensitivity, specificity, false positive rate, false negative rate and overall accuracy of FNAC in the diagnosis of thyroid nodules was 87.1%(101/116), 95.3%(102/107), 4.7%(5/107), 12.9%(15/116), 91.0%(203/223). CONCLUSIONS: FNAC is a reliable diagnostic method for evaluation of thyroid disease. TBSRTC is a accurate and effective reporting system for cytopathological diagnoses, so it is worthy of being widely popularized in clinical application.