Follicular and Hürthle cell thyroid neoplasms. Is frozen-section evaluation worthwhile?

OBJECTIVES: To determine whether (1) frozen-section (FS) evaluation of follicular and Hürthle cell thyroid neoplasms (FHCNs) is accurate, (2) FS aids in intraoperative decision-making, and (3) FS is cost-effective.

DESIGN: Retrospective review of patient histories and FS and paraffin-embedded slides. Permanent histologic sections were considered the standard criterion. Follow-up was achieved in 92% of patients with a mean follow-up of 5.7 years.

SETTING: Tertiary care referral center.

PATIENTS: All patients undergoing thyroidectomy for a suspected FHCN between January 1, 1985, and December 31, 1994. Patients included were those whose condition was diagnosed as FHCN, either on FS, permanent histologic sections, or both.

MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FS analysts were determined. Total adjusted hospital charges were compared for those undergoing 1 vs 2 cancer operations. Multivariate analyses were carried out to determine the optimal predictive model for follicular cancer.

RESULTS: The study group included 1023 patients (737 women and 286 men), of whom 83 (8.1%) were diagnosed as having a malignant FHCN on permanent section. The diagnosis of malignant neoplasm was correctly established in 65 (78%) of the 83 patients on FS, thereby permitting definitive surgical management at the first operation. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for FS diagnosis of malignant FHCN were 78%, 99%, 90%, 98%, and 98%, respectively. In a multivariate analysis, FS was the most significant variable predictive of malignant neoplasm. Approximately $400,000 was saved in hospital charges by the use of FS as a result of the elimination of many 2-stage operations.

CONCLUSION: Frozen-section evaluation of FHCN can be performed with a high degree of accuracy, permitting considerable cost savings.