Interest of fine-needle aspiration cytology in thyroid nodule

Objectives: The aim of the present study was to evaluate our technique of thyroid fine-needle aspiration cytology (FNAC), its limitations and means of improvement by comparing our results with those of literature. Material and methods: Thyroid FNAC results from 117 consecutive patients (May 2006 to July 2007) were categorized into four groups: benign, with suspected malignancy, malignant and unrepresentative. The FNAC results were compared with histopathologic analysis after thyroidectomy. Results: All "benign'' and "malignant'' FNAC findings were confirmed on final histology. All "suspect'' FNAC findings were benign on histology. Cytological diagnosis of malignancy was consistent with histological examination in all cases. Sensitivity was 100% (no false negatives), specificity 67% (28% false positives), positive predictive value 72% and negative predictive value 100%. There was a significant difference in the proportion of "unrepresentative'' results between two of the operators performing aspiration (51% versus 29.2%). Conclusions: The main pitfall of FNAC in thyroid pathology is the "suspect'' category, for which positive diagnosis is founded on histological criteria alone. The second limitation identified in this study was the high number of "unrepresentative'' aspirates. However, the technique remains useful. (C) 2011 Published by Elsevier Masson SAS.