- The aim of this study was to determine the accuracy and clinical utility of fine needle aspiration (FNA) for the preoperative diagnosis of patients presenting with solitary thyroid nodules. Between 1987 and 1991, 317 patients with a thyroid nodule underwent FNA. Surgery was performed on 98 of the patients, and the cytologic findings were correlated with the final histologic diagnoses for these cases. Of the 98 patients operated on, satisfactory aspirates were obtained in 85 patients and classified as either malignant, suspicious for malignancy, or benign. The FNA was correct in predicting malignancy in 29 of 35 nodules (82.9%). With the benign nodules, FNA was correct in 44 of 50 nodules (88%). The overall accuracy of FNA was 85.9%. The accuracy for the combination of FNA and frozen section (FS) was 92.6%. We conclude that both FNA and FS are accurate tests that play a useful role in the pre- and intraoperative diagnostic evaluation of patients presenting with solitary thyroid nodules.