UTILITY OF FINE-NEEDLE ASPIRATION CYTOLOGY AND FROZEN-SECTION EXAMINATION IN THE OPERATIVE MANAGEMENT OF THYROID-NODULES

Fine-needle aspiration cytology has a high sensitivity for the diagnos is of solitary thyroid nodules. Certain diagnoses involving follicular histologies often cannot be made with needle biopsy alone. The utilit y of frozen-section examination of thyroid nodules, with particular re gard to those lesions with follicular histologies, is also limited. We examined the correlation of fine-needle aspiration cytology and froze n-section examination in solitary thyroid nodules to determine the con tribution of frozen-section examination to the operation. We reviewed the fine-needle aspiration cytology, frozen-section examination, and f inal pathology of 100 consecutive patients undergoing thyroidectomy fo r a solitary solid thyroid nodule in an 4-year period. The diagnoses w ere classified as indeterminant, benign, or malignant. The utility and impact of the diagnosis from fine-needle aspiration or frozen section on the operative procedure performed was analyzed. Fine-needle aspira tion cytology as a diagnostic test for thyroid nodules demonstrated an indeterminant rate of 23 per cent, with a diagnostic accuracy of 77 a nd 92 per cent for benign and malignant disease, respectively. In all patients with inaccurate benign diagnosis on fine-needle aspiration cy tology, follicular neoplasm was misinterpreted for follicular adenoma or multinodular goiter. In comparing frozen-section results, the indet erminant, benign, and malignant rates were 7, 96, and 64 per cent, res pectively. Of the 23 patients with indeterminant results on fine-needl e aspiration cytology, the intraoperative frozen-section diagnosis on 4 patients was deferred to permanent section; 18 received accurate cyt ological diagnosis; and in 1 patient, carcinoma was missed. Overall, t he decision about the extent of surgical thyroid resection was changed in only 2 patients based on the frozen-section results. Preoperative evaluation with fine-needle aspiration cytology can accurately and app ropriately define the extent of thyroid surgery in most patients with a diagnosis of malignant neoplasm or benign disease. Intraoperative fr ozen-section examination may be helpful if fine-needle aspiration cyto logy results are inderminant and in cases of follicular histology as a n adjunct for evaluation of the thyroid nodule, but overall, frozen se ction does not contribute to the management of the thyroid lesion at t he time of surgery.