Fine-needle aspiration (FNA) biopsy is considered the routine initial and the most cost-effective procedure in the evaluation of thyroid nodules. Notwithstanding the advantages of the procedure, it depends heavily on the pathologist's experience and on technical skills to obtain adequate smears. The aim of this paper is to evaluate the procedure efficacy in a general teaching hospital. Smears obtained from 754 FNA were examined over a 3-year period. Each palpable nodule was aspirated by an endocrinology resident with a fine-needle 4 to 6 times. Material were stained by Giemsa and Papanicolaou techniques. Histopathologic examination was done on 93 patients. FNA biopsy was performed in 663 patients (613F/50M), mean age of 50±14 years (range 12 - 93). FNA results were: colloid nodule (58.5%), follicular neoplasm or suspicious (8.2%), Hashimoto's thyroiditis (5.3%), papillary carcinoma (2.3%), anaplastic carcinoma (0.4%), medullary carcinoma (0.1%), and unsatisfactory (25.2%). Neoplasias were detected in 41 (44%) of 93 surgeries undertaken, and most of the carcinomas were of papillary type (65.6%). There were 24% follicular carcinomas among the follicular neoplasms. The FNA data analysis revealed: sensitivity 92% (CI= 78.6 to 98.3%), specificity 80% (CI= 65.4 to 90.4%), positive predictive value 79.5% (CI= 64.7 to 90.2%), negative predictive value 92.3% (CI= 79.1 to 98.4%), and accuracy 86% (CI= 76.1 to 92.3%). FNA established a diagnosis in 66.6% of the patients, decreasing costs and the number of surgeries. As a result of better patient selection, the yield of thyroid carcinomas in excised nodules has increased from 19.4% to 31.2% in a period of 11 years in our hospital.
Thyroid nodule; Fine-needle aspiration biopsy; Thyroid neoplasm; Thyroid cancer; Citopathology
