Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jul 31;12(7):884-893.
doi: 10.21037/gs-22-491. Epub 2023 Jul 4.

Malignancy risk in Bethesda class IV thyroid nodules in an iodine deficient region

Tommaso Loderer  1 , Elena Bonati  1 , Valentina Donato  1 , Lorenzo Viani  1 , Federico Cozzani  1 , Paolo Del Rio  1
Affiliations

Malignancy risk in Bethesda class IV thyroid nodules in an iodine deficient region

Tommaso Loderer et al. Gland Surg. .

Abstract

Background: According to the latest guidelines, in patients with high-risk nodules with indeterminate cytology, diagnostic lobectomy should be the preferable surgical approach in the absence of factors that suggest a total thyroidectomy.

Methods: This retrospective observational study has as its main aim the evaluation of the cases that underwent surgery, for Bethesda class IV nodules in our iodocarent geographical area. Particular attention was paid to carcinoma incidence, preoperative nodule size, histological characteristics of the neoplasm, surgical approach and eventual need of radiometabolic treatment. A total of 320 patients were included that underwent surgery for Bethesda IV nodules, between January 2010 and December 2020, at the General Surgical Clinic of the University Hospital of Parma, Italy.

Results: A total of 230 total thyroidectomies (71.9%) and 90 lobectomies (28.1%) were performed. Our data showed a strong impact of the 2015 ATA Guidelines on the surgical approach choice, with a progressive propensity towards a conservative approach and an increase of lobectomies from 7.2% to 41.5% after the new guidelines introduction. However, in our sample the percentage of lobectomies remains below 50%; this data is certainly influenced by the number of cases of multinodular pathology, often bilateral, in our geographical area. The nodules malignancy rate resulted 28.8%. Our data showed that increasing size correlated with an increasing malignancy rate (P<0.01), and follicular carcinomas were found to be larger than papillary carcinomas (P<0.001). A statistically significant correlation also emerged between nodule size increase and local/lymphovascular invasion (P<0.05). On the other hand, there was no statistically significant correlation between nodule size and multifocality, and between nodule size and presence of lymph node metastases. Out of the patients where it was possible to find this data, 66% underwent radioiodiometabolic treatment: 59% with papillary carcinoma, and 85% with follicular carcinoma.

Conclusions: In patients with Bethesda IV thyroid nodules, diagnostic lobectomy should be the preferable surgical approach in absence of factors that suggest total thyroidectomy. In our opinion, total thyroidectomy remains the first choice in large nodules (≥4 cm) as these nodules have a high malignancy rate, greater local/lymphovascular invasion and a consequent frequent indication for post-operative radiometabolic treatment.

Keywords: Bethesda system; Indeterminate cytology; lobectomy; thyroidectomy.

PubMed Disclaimer

Conflict of interest statement

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-22-491/coif). The authors have no conflicts of interest to declare.

Figures

Figure 1
Figure 1
Preoperative nodules size distribution (overview of the nodule size of the patients treated).
Figure 2
Figure 2
Comparison between pre- and post-operative size of thyroid carcinomas. CI, confidence interval.
Figure 3
Figure 3
Correlation between preoperative size and diagnosis of papillary and follicular carcinoma lymph node metastases. CI, confidence interval.
Figure 4
Figure 4
Correlation between preoperative size, local/vascular invasion and multifocality. CI, confidence interval.
Figure 5
Figure 5
Correlation between preoperative size and lymph node metastases. CI, confidence interval; N, nodes.
See this image and copyright information in PMC

Comment in

References

    1. AIOM. Linee guida tumore della tiroide 2021. Available online: https://www.aiom.it
    1. Laurberg P, Cerqueira C, Ovesen L, et al. Iodine intake as a determinant of thyroid disorders in populations. Best Pract Res Clin Endocrinol Metab 2010;24:13-27. 10.1016/j.beem.2009.08.013 - DOI - PubMed
    1. Barrea L, Gallo M, Ruggeri RM, et al. Nutritional status and follicular-derived thyroid cancer: An update. Crit Rev Food Sci Nutr 2021;61:25-59. 10.1080/10408398.2020.1714542 - DOI - PubMed
    1. Haugen BR, Alexander EK, Bible KC, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid 2016;26:1-133. 10.1089/thy.2015.0020 - DOI - PMC - PubMed
    1. Russ G, Bonnema SJ, Erdogan MF, et al. European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules in Adults: The EU-TIRADS. Eur Thyroid J 2017;6:225-37. 10.1159/000478927 - DOI - PMC - PubMed