Endocrine Abstracts

JOINT1999

Introduction: Nodular thyroid pathology poses the problem of its histological nature on which the therapeutic approach depends. Intraoperative frozen section, by giving the rapid diagnosis of benignity or malignancy, conditions the immediate surgical procedure. The aim of this work is to study the sensitivity and specificity of intraoperative frozen section in thyroid pathology and to identify its limits.

Materials and Methods: This is a retrospective study having collected over a period of two years, 120 patients operated on for thyroid pathology. The average age was 46 years (range 15 to 84 years). A female predominance was noted with a sex ratio of 0.17. Preoperative thyroid cytology was performed in 9 cases. The tumors were benign in 77 cases (64.2%) and malignant in 43 cases (35.8%). We compared the results of intraoperative frozen section with the definitive histological examination.

Results: The intraoperative frozen section concluded to a benign lesion in 90 cases (75%), a malignant lesion in 29 cases (24.1%). It was doubtful in one case (0.9%). The doubtful case corresponded to a malignant lesion on the definitive histological examination. No false positive (FP) was reported. The sensitivity of the extemporaneous examination for all histological types was 69% and the specificity was 100%. The predictive positive value was 100% and the predictive negative value was 85.5%. The diagnostic efficiency was 88.3%.

Conclusion: The reliability of the intraoperative frozen section of the thyroid is widely demonstrated. Our study showed a perfect specificity of this examination; however the difficult interpretation of thyroid lesions of follicular architecture and microcarcinomas explains a sensitivity of 69%.