Frozen Section of Thyroid? Just Say No, Again

Utility of Routine Frozen Section of Thyroid Nodules Classified as Follicular Neoplasm

OBJECTIVES

To evaluate the diagnostic performance of frozen section in thyroid nodules classified as follicular neoplasm.

METHODS

A diagnostic test meta-analysis was designed. Studies that assessed frozen section in patients with thyroid nodules and a fine-needle aspiration biopsy result of Bethesda IV were selected. The outcomes measured were the number of false- and true-positive and -negative results. We used the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) instrument for methodological quality assessment and a bivariate mixed-effects regression framework and a likelihood-based estimation of the exact binomial approach.

RESULTS

Forty-six studies from 1991 to 2018 were included. Most studies had moderate methodological quality. The overall sensitivity and specificity were 43% (95% confidence internal [CI], 0.34-0.53) and 100% (95% CI, 0.99-1.00), respectively. The hierarchic summary receiver operating characteristic curve showed an area under the curve of 0.91 (95% CI, 0.80-0.97).

CONCLUSIONS

Frozen section demonstrates moderate diagnostic performance in patients with follicular neoplasm, and its utility for making intraoperative decisions is limited. Its routine use should be discouraged.

Utility of intraoperative frozen sections for thyroid nodules with prior fine needle aspiration cytology diagnosis

INTRODUCTION

The objective of this study was to evaluate the role of intraoperative frozen section (IFS) in determining the course of surgery in thyroid nodules with a prior fine needle aspiration (FNA) biopsy diagnosis. In addition, reliability of FNA interpretation to guide surgical management without IFS was investigated.

MATERIAL AND METHODS

This is a retrospective study of all patients who had a FNA biopsy, IFS, and final pathology performed on a thyroid nodule over a 9 month period. The extent of surgery at the time of the IFS was recorded. Subsequent change in surgical procedure following the IFS diagnosis was noted in each of the Bethesda diagnostic categories.

RESULTS

55% of the cases were deferred at IFS overall, with 68 and 86% in Bethesda III and IV categories, respectively. Overall, there was a change in management in 6% of cases.

CONCLUSIONS

Our study does not support the use of IFS for nodules with prior FNA interpretation of Bethesda II, III, IV and VI as management was not significantly changed. IFS is of value for nodules with prior FNA diagnosis of Bethesda I for interpretation of nodule, and Bethesda V for planning surgery. A confirmatory diagnosis could not be rendered at IFS for lesions with follicular architecture, which comprised most of the cases in Bethesda III and IV.

Surgeon-performed ultrasound predictors of malignancy in patients with Hürthle cell neoplasms of the thyroid

BACKGROUND

Fine-needle aspiration cannot reliably determine malignancy in patients with Hürthle cell neoplasms (HCNs) of the thyroid. Thyroid nodule size and characteristics determined by surgeon-performed ultrasound (SUS) may be useful for predicting malignancy in HCN preoperatively. This study examined whether tumor size and features by SUS can reliably predict malignancy in patients with HCN.

MATERIALS AND METHODS

We performed a retrospective review of 84 patients with HCN by fine-needle aspiration, who underwent SUS and thyroidectomy from 2002 to 2010. All patients underwent thyroid lobectomy with isthmusectomy unless there was a history of radiation exposure, familial thyroid cancer, obstructive symptoms, bilateral nodules, and/or patient preference, in which case total thyroidectomy was performed. Tumor size and malignant features by SUS were correlated with final histopathology using multivariate regression analysis.

RESULTS

On final histopathology, 29 patients had malignant thyroid nodules and 55 patients had benign ones. There were no statistically significant differences in terms of age, race, ethnicity, or gender between HCN patients who revealed malignant or benign nodules on final pathology. Tumor size ≥ 4 cm measured by SUS did not predict malignancy in HCN. Hypoechogenicity and hyperechogenicity were significantly associated with malignancy, whereas isoechogenicity was predictive of benignity (P = 0.044). No other ultrasonographic features were predictive for thyroid carcinoma by multivariate analysis.

CONCLUSIONS

Tumor size and features determined by SUS do not reliably predict malignancy in patients with HCN. Such patients at risk for malignancy should initially undergo thyroid lobectomy for definitive diagnosis.