“Analysis Of Correlation Of Fine Needle Aspiration Cytology With Histopathology Finding In Thyroid Lesion”

Abstract

Background and objectives:

Fine-needle aspiration cytology (FNAC) is currently employed in evaluating thyroid nodules which harbour malignancy. Fine-needle aspiration cytology is of pivotal diagnostic importance for clinicians in evaluating thyroid nodules and aids in preventing unindicated thyroid surgeries. Studies across the globe have evaluated and compared FNAC (with the Bethesda system of scoring) and histopathology assessment of the thyroid lesions with differing outcomes. Multiple studies from across the globe as well as India have tried to compare the two modalities. In order to garner specific insights on role of FNAC versus histopathology in patients with suspected thyroid swellings visiting our institute for management, we decided to conduct this study. The study is expected to contribute to the limited literature focussing on this domain in the subsets of Indian populations catered to at our center.

Materials and Methods:

The study was done at the Department of Surgery in the ACS medical college and hospital, Chennai. Data of 50 patients who presented to the department with thyroid swellings due to various causes was included in the analysis. An FNAC was performed and subsequently histopathological evaluation was done to assess the diagnosis of the thyroid disorders. A diagnostic accuracy assessment of FNAC vs histopathology was done.

Results:  In the current study, it was seen that histopathology and FNAC corelated highly in terms of diagnosis of various thyroid lesions. Of the 41 cases identified as colloid goitre on FNAC, 39 were confirmed as accurate by the histopathology (95.12%). In terms of the malignant causes, high degree of agreement was seen for follicular neoplasm but only half the cases of papillary carcinoma were confirmed by histopathology suggesting some false positive rate for papillary CA on FNAC. Overall, there was a high degree of corelation (90% concordance) between the findings of FNAC and the histopathology. An assessment of the benign vs malignant lesions was seen done basis the FNAC and histopathology findings. 48 patients (96%) were accurately identified as benign or malignant by the FNAC as confirmed by the histopathology later on. 2 patients were seen to have a mismatch in terms of FNAC and histopathology findings. The results were significant statistically with a P value of <0.0001. The sensitivity and specificity of FNAC was seen to be 83.33% and 97.73%. The PPV and NPV for FNAC was 83.33% and 97.73%. The overall accuracy of FNAC was 96%.

Conclusion:

The study was able to conclude that FNAC was a very useful modality for the diagnosis and management of the thyroid swelling. FNAC was seen to have very high accuracy in terms of characterisation of the thyroid swelling. The sensitivity and specificity of FNAC was seen to be 83.33% and 97.73%. The PPV and NPV for FNAC was 83.33% and 97.73%. The overall accuracy of FNAC was 96%. There was a high degree of corelation (90% concordance) between the findings of FNAC and the histopathology. The findings of this study were in line with the major published literature in this domain both nationally and internationally