Fine needle aspiration biopsy of thyroid nodules: Cytohistological Correlation

Abstract

OBJECTIVE: Fine-needle aspiration biopsy (FNAB) currently is the main procedure for distinguishing benign from malignant thyroid nodules. The aim of our study was to assess the accuracy of FNABs in our hospital by comparing the cytological and histological diagnosis. METHODS: We performed a prospective study including 321 patients with thyroid nodules admitted to St. Marina Hospital from January 2004 to December 2006. Clinical and US data, TSH, FT3, FT4, anti-TPO, cytological and histological findings were evaluated. RESULTS: FNABs were performed in all 321 cases, 290 of them were women and 31 men; mean age 52,9 years. Cytological evaluation considered 67,3% of FNABs as benign, 15,6% as suspicious, 4,7% as malignant and 12,4% as inadequate sample. 88 of the patients underwent thyroid surgery. The comparison between cytological and histological findings showed that 99,1% of cytologically benign nodules were histologically confirmed, as well as 100% of the malignant lesions. 89,5% of the cases classified as suspicious on FNAB turned out to be benign on histology and 10,5% were malignant. The discrepant cases were 2 false-negative results, which had a cytological diagnosis of nodular hyperplasia and turned out to be a medullary carcinoma. Our results showed a sensitivity of 88,2% and a specifity of 100%. CONCLUSION: Thyroid FNAB is an accurate and cost-effective preoperative tool for selection of patients who would benefit from surgery. Scripta Scientifica Medica 2008;40(1):39-42