To Establish Bethesda System for Diagnosis of Thyroid Nodules on the Basis of Fnac with Histopathological Correlation.

Abstract

In October 2007, "The National Cancer Institute (NCI), Thyroid Fine Needle Aspiration State of the Science Conference" was held in Bethesda, Maryland hosted by the NCI with the intention of formulating internationally acceptable guidelines for reporting of thyroid cytopathology. This was because, thyroid FNAC have a reporting confusion due to multiplicity of category terminologies. To overcome this, The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) was introduced for unifying the terminology and morphologic criteria along with the corresponding risk of malignancy. The Bethesda system for reporting thyroid cytopathology represents a major step towards standardization, reproducibility, improved clinical significance, and greater predictive value of thyroid fine needle aspirates (FNAs). The aim of this study was to elucidate the diagnostic utility of the Bethesda system in reporting thyroid FNAs and to assess the effectiveness of FNAC in the evaluation of thyroid nodules by comparing the results with histopathological evaluation. The present study was carried out in our institute during the July 2012 to September 2014. In this study, 100 FNACs done which were classified according to the Bethesda system and out of them, 60 histopathological evaluations obtained from this group were evaluated. The sensitivity, specificity, positive and negative predictive values were evaluated. Out of 100 FNACs, 06% were Non-diagnostic, 78% were Benign, 04% were Atypical follicular lesion of undetermined significance (AFLUS), 04% were suspicious for Follicular neoplasm (SFN), 01% were suspicious for Follicular neoplasm Hurthle cell type, 03% were suspicious for malignancy (SM), and 04% malignant. In 60 cases, data of follow-up histopathologic examination (HPE) were available. The sensitivity was 88.89% and specificity was 84.31%. The positive and negative predictive value were 50% and 97.7%, respectively. The Bethesda system is very useful for a standardized system of reporting thyroid cytopathology, improving communication between cytopathologists and clinicians, and inter-laboratory agreement, leading to more consistent management approaches. An additional point which is in favor of the implementation of this system is that the classification is directly related to the risk of malignancy in each category, which in turn, prompts the recommended clinical management of that category, thus truly embodying the clinico-pathological correlation in its true spirit. The correlation of FNAC with histopathology is necessary before starting treatment.