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Diagnostic value of FNA in thyroid nodules

Thyroid nodules are one of the most common problems, especially in endemic areas, and their importance is due to probability of cancer. Because FNA is easy and cost-effective, it is usually the first step in diagnosis and evaluation of these nodules. This method is highly dependent on the clinician’s skill and pathologist’s experience. In this prospective study, 153 patients (112 F, 41 M, F/M= 2.73) from 1997-2000 in Bank Melli Hospital were studied. The mean age±SD of patients was 40.5±13 years. FNA was done for all of these patients and results of FNAs and surgical specimens of these patients were reported by a single pathologist. On FNA, 133 cases (87%) were nonmalignant (including colloid cyst, colloid adenoma, nodular hyperplasia, thyroiditis), 10 cases (6.5%) were suspicious, 6 cases (3.9%) were papillary carcinoma, 3 cases (2%) were follicular carcinoma and 1 case (0.65%) was Hurthle cell carcinoma. The results of pathologic specimens were as follows: 125 (81.7%) were multinodular or nodular goiter, 16 (10.4%) were papillary carcinoma, 3 (3.2%) were follicular carcinoma, 1 (0.65%) was Hurthle cell carcinoma, and 8 (5.2%) were Hashimoto’s thyroiditis. FNA sensitivity was 75%, specificity was 97%, positive predictive value was 79%, and negative predictive value was 95.5%. The percentage of malignancy of nodules in males (24.4%) was significantly (P<0.05) greater than in female (8.9%) as shown in other studies. FNA is a suitable method for cancer diagnosis in thyroid nodules with an acceptable specificity and NPV. Precise sampling and pathologist’s expertise would increase the sensitivity and PPV. Keywords: