Frozen section in thyroid gland follicular neoplasms: It's high time to abandon it!

The Role of Frozen Section Examination in Thyroid Surgery

In endocrine pathology, frozen section (FS) examination is most commonly used for the intraoperative evaluation of thyroid and parathyroid tumors, as well as cervical lymph nodes. In the past, frozen section was considered a fundamental tool in thyroid surgery. However, with advancements in preoperative ultrasound and fine-needle aspiration biopsy (FNAB), there have been increasing queries about its routine use due to the improved preoperative diagnosis. Nowadays, while the use of FS during thyroidectomy has decreased, it is still used as an additional method for different purposes intraoperatively. FS may not always provide definitive results. If FS will alter the surgical plan or extent, it should be applied. Routine FS is not recommended for evaluating thyroid nodules. But in addition to FNAB, if FS results may change the operation plan or extent, they can be utilized. FS should not be applied for thyroid lesions smaller than 1 cm, and the entire lesion should not be frozen for FS. For the assessment of thyroid nodules, the use of FS is recommended based on the Bethesda categories of FNAB. In Bethesda I category nodules, FS may contribute to distinguishing between malignant and benign lesions and guide surgical treatment. In Bethesda II nodules, where the malignancy rate is low, the performance of FNAB and FS can be compared, but it's not recommended due to the lack of a significant contribution to the surgical strategy. The sensitivity of FS in Bethesda III and IV nodules is low; its contribution to the diagnosis is limited, and it does not provide an apparent benefit to treatment; therefore, it is not recommended. In Bethesda V nodules, FS can effectively confirm the malignancy diagnosis, contribute to the surgical strategy, and reduce the possibility of completion thyroidectomy, and accordingly, it is recommended for use. Nonetheless, in Bethesda V nodules with a benign FS report, the malignancy rate remains high, so it should not be used to rule out malignancy. In Bethesda VI nodules, the performance of FS is lower or comparable to FNAB and does not significantly contribute to the treatment strategy; hence, it is not recommended. Particularly in patients with papillary thyroid cancer, intraoperative FS can be effective in detecting extrathyroidal extension and can assist the surgeon in determining the extent of thyroid surgery and central neck dissection. FS has high sensitivity and specificity in evaluating the lymphatic status of the central region intraoperatively and can be used to determine the extent of central compartment node dissection. During thyroidectomy, FS examination can be used in recognizing parathyroid tissue and distinguishing it from fatty tissue, thymus, thyroid, lymph nodes, especially in differentiating metastatic lymph nodes.

To Freeze or Not to Freeze? Recommendations for Intraoperative Examination and Gross Prosection of Thyroid Glands

The use of intraoperative consultation for indeterminate thyroid lesions is not advocated but is still requested by some surgeons. Obscured cytomorphology and nonrepresentative sampling limit the specificity of intraoperative assessment. Formalin fixation of thyroid glands before sectioning also minimizes artifacts introduced by fresh sectioning. Inking of thyroid may vary based on institutional preferences and information desired by clinical teams. Sectioning may occur in the conventional transverse method or the modified transverse vertical method to more thoroughly evaluate the lesion's periphery. Gross examination of thyroid lesions should always consider possible high-grade features, such as necrosis or extrathyroidal extension.

The Use of Artificial Intelligence in the Diagnosis and Classification of Thyroid Nodules: An Update

The incidence of thyroid nodules diagnosed is increasing every year, leading to a greater risk of unnecessary procedures being performed or wrong diagnoses being made. In our paper, we present the latest knowledge on the use of artificial intelligence in diagnosing and classifying thyroid nodules. We particularly focus on the usefulness of artificial intelligence in ultrasonography for the diagnosis and characterization of pathology, as these are the two most developed fields. In our search of the latest innovations, we reviewed only the latest publications of specific types published from 2018 to 2022. We analyzed 930 papers in total, from which we selected 33 that were the most relevant to the topic of our work. In conclusion, there is great scope for the use of artificial intelligence in future thyroid nodule classification and diagnosis. In addition to the most typical uses of artificial intelligence in cancer differentiation, we identified several other novel applications of artificial intelligence during our review.

The Accuracies of Fine-Needle Aspiration Biopsy without Ultrasound Guidance versus Frozen-Section Examination of Thyroid Nodule Diagnosis in Teaching Hospital Universitas Sumatera Utara: Single-Center Experience

BACKGROUND: The urgency to determine the most applicable methodological approach in thyroid nodules diagnosis workup is unquestionably important due to a significant increase in its prevalence globally. To date, fine-needle aspiration biopsy (FNAB) is the most recommended procedure to diagnose preoperatively even though the certain role of frozen-section examination (FSE) intraoperatively were significant as well to be administered at some circumstances. AIM: This study aims to measure the diagnostic accuracies of FNAB and FSE and determine the role of each procedure in the current thyroid nodules’ workup. MATERIALS AND METHODS: This retrospective study was conducted at teaching hospital of Universitas Sumatera Utara, Indonesia. We included and investigated both FNAB and FSE in 106 patients; the results were compared to the final histopathological report, in which statistical analyses were conducted. RESULTS: Most of the nodules are malignant after histopathological confirmation. From the fourfold contingency table, we were able to subtract several diagnostic parameters of the procedures. The FSE substantially disclosed better performance in sensitivity, specificity, positive predictive value (PPV), negative predictive value, and remarkably the accuracy. After several in-depth analyses, it is apparent that a higher rate of false-negative in FNAB is inducing its substandard performance, especially when the guidance of ultrasonography was not applied in this study. Furthermore, an analysis toward the concordance between both procedures results is revealing a significant improvement on almost every parameter, indicated by 100.0% specificity and PPV. CONCLUSION: Although the outcomes in this study are not corresponding to the current guidelines, we acknowledged several limitations in this study, However, the role of FSE in thyroid nodule workup should be reconsidered since we found that the procedure is exhibiting a potential to assist the current method, even though the influence of its certain pitfall remained questionable.