Clarifying the role of fine-needle aspiration cytologic evaluation and frozen section examination in the operative management of thyroid cancer.

The final histologic diagnoses of 486 patients who underwent thyroidectomy at UCLA Medical Center from March 1975 to August 1988 were reviewed. There were 146 patients with a diagnosis of thyroid malignant neoplasm. All patients who had preoperative fine-needle aspiration cytologic evaluation, intraoperative frozen section analysis, or both were included in the present study. Carcinoma was diagnosed by frozen section in 87 (69%) of 126 cases. Frozen section analysis was incorrect in 39 (31%) of 126 cases. Fine-needle aspiration was performed in 62 patients. A malignant neoplasm was identified by fine-needle preoperative fine-needle aspiration and intraoperative frozen section analysis, and carcinoma was detected by both methods in 32 (57%) of 56 cases. Fine-needle aspiration cytologic evaluation is extremely valuable in the diagnosis of thyroid cancer and is at least as accurate as frozen section analysis with less morbidity and expense. When fine-needle aspiration demonstrates malignant neoplasm, thyroid resection may be planned with confidence.