[Evaluation of fine needle aspiration cytology in the diagnosis of thyroid diseases].

The role of fine needle aspiration cytology (FNA) was examined in 384 patients with thyroid diseases referred to the thyroid clinic from May 1984 to June 1988. The cytological diagnoses were 65 (16.9%) malignant neoplasms, 137 (35.7%) benign neoplasms, 135 (35.2%) chronic thyroiditis, 20 (5.2%) thyroid cysts, and 27 (7.0%) other thyroid diseases including Graves' disease and subacute thyroiditis. Ninety-eight patients were selected for thyroidectomy based on criteria, which included clinical and cytological diagnosis, and the following pathological diagnoses of resected specimens were obtained: 45 (45.9%) papillary carcinoma, 9 (9.2%) follicular carcinoma, 26 (25.5%) follicular adenoma, 1 (1.0%) papillary adenoma, 14 (14.3%) adenomatous goiter, and 3 (3.1%) Hürthle cell adenoma. The accuracy of diagnosis of goiter by FNA was examined by comparing with that by histological findings. False negative rate, false positive rate, true positive rate, and true negative rate of FNA were 5.7%, 10.0%, 94.3%, and 90.0% respectively. The calculated sensitivity, specificity, and accuracy of FNA were 92.6%, 92.3% and 92.5% respectively. These results indicate that the FNA is a safe and reliable method for routine use in the evaluation of nodular thyroid disease.