Evaluation of non-palpable thyroid nodules by ultra sound guided fine needle aspiration cytology

Abstract

The aim of this study was to see the usefulness of fine needle aspiration by “theBethesdasystem for reporting Thyroid Cytopathology” (TBS- RTC) for non palpable thyroid nodules through ultrasound-guidance for the evaluation and treat ment planning of nonpalpable thyroid lesions. This study was conducted on 200 patients with non palpable thyroid nodules which are very low lying or felt on swallowing; in Department of Pathology and Radiology since January 2011 to June 2012. The patients were scanned and USG- FNAC was performed and reporting was done by “TBSRTC”. Of the 200 specimens 17 samples were nondiagnostic or unsatisfactory (Class I), 145 samples were benign (Class II), 20 samples were showing Atypical of Undetermined Significance (AUS) or Follicular Lesion of Undetermined Significance (FLUS); (Class III), 6 were showing follicular neoplasm or suspicious for a follicular neoplasm (Class IV), 7 samples were suspicious for malignancy (Class V) and 5 samples were positive for malignancy (Class VI). On comparison of ultrasound guided FNAC with histopathology the sensitivity for correct diagnosis was 93%, specificity was 86%, positive predictive value was 37%, negative predictive value was 99% and accuracy was 86%. USG-FNAC is a useful modality for the evaluation and treatment planning of nonpalpable thyroid lesions smaller than5 mmin the maximum diameter. TBSRTC is the best method of reporting but class III and IV are the main pitfall of this system for reporting Thyroid Cytopathology and show high sensitivity, specificity and accuracy.