Last update:
10-Sep-2004

OBJECTIVE The role of frozen section in intraoperative diagnosis is well established. The limitations of the method in certain thyroid lesions raise the question of whether frozen section affects intraoperative decision making in thyroid surgery.

METHOD The frozen section and subsequent permanent histologic diagnosis of 252 surgical specimens of thyroid, resected from an equal number of patients (220 females, 32 males) aged 17-85 (median 48.5) years were evaluated retrospectively. A preoperative diagnosis was recorded in all but 17 cases, including "goiter", "cold nodule", "cyst", "Hashimoto's thyroiditis", "cancer" or "thyroid enlargement/tumor".

RESULTS According to the final histologic diagnosis there were 179 goiters, 31 follicular adenomas, 34 malignant neoplasms, 6 cysts and 2 cases of Hashimoto's thyroiditis. The results of frozen section examination correlated with the preoperative diagnosis in all non-neoplastic cases and in 14 carcinomas. Of the remaining malignant tumors (n=20), with a preoperative diagnosis of "cold nodule/goiter", frozen section diagnosis changed the surgical planning in 9 cases. Finally, 22 follicular adenomas were diagnosed on frozen section as "follicular neoplasms" and 9 as "benign lesions".

CONCLUSIONS The results of the present study show that frozen section diagnosis confirms the preoperative diagnosis in all cases of non-neoplastic thyroid lesions and in the majority of malignant lesions. The decisive influence of frozen section in surgical procedure was critical only in 3.5% of the total thyroid cases (9/252). The main limitation of the method is its inability to distinguish benign follicular tumors from their malignant counterparts.

Key words: Carcinoma, Follicular neoplasm, Frozen section, Thyroid.