Endocrine Abstracts

Background

The prevalence of malignancy among Bethesda category III (atypia of undetermined significance) cytologies is variable in different studies.

Objective

The aim of this paper is to evaluate the risk of malignancy of thyroid nodules classified as Bethesda III in our hospital.

Methods

We have reviewed the medical records of 146 patients who underwent FNA with Bethesda III results between January 2017 and June 2020 in our hospital. From those, 26 patients were excluded because they didn’t have enough follow -up information (n = 120). We analyzed the result of the second FNA (in those patients in which it was performed), then, the histological result from surgery and the echographic characteristics of each nodule.

Results

The mean age of the patients at the time the FNA was performed was 57, 16±11, 7 years. 71, 67% of them were women. A second FNA was performed in 65.83% of the patients (79/120) resulting in Bethesda 1 (non-diagnostic) 29.11% of them, 2 (benign) in 40.51%, 3 (undetermined) in 24.05%, 4 (suspicious for follicular neoplasm) in 1.27% and 5 (suspicious for malignancy) in 5.06% of them. 33.33% of all the patients suffered from hypothyroidism (40% of them had a benign nodule and 17.5% had a malign one). In 61 patients surgery was indicated: 57.38% had a hemithyroidectomy and 42.62% had a total thyroidectomy. Postsurgical complications occurred in 14.76% of the patients (6.56% suffered from dysphonia, 6.56% partial recurrent laryngeal nerve paralysis and 1.64% hypoparathyroidism). These complications appeared in 19.23% from total thyroidectomized patients, against 11.42% of hemithyroidectomized ones. From the 61 patients undergoing surgery, the histology was benign in 62.29% of the cases and malignant in 36.07% (26.6% were papillary thyroid cancer, 3.27% follicular thyroid cancer, 3.27% NIFTP and 3.27% Hürthle cell carcinoma). In addition, the ultrasound characteristics of benign and malignant nodules were compared. From those with malignant histology, 13.63% showed microcalcifications (compared to 7.89% of benigns); 31.81% had irregular margins (compared to 7.89% of benigns); 54.54% had hypoechoic consistency (vs 36.84% in benigns) and 36, 36% showed absent of hypoechoic halo (vs 47.36% of benigns) 52.63% of benign nodules occurred in the context of multinodular goiter (compared to 31.81% of malignant nodules).

Conclusion

More than one third of the Bethesda III patients who underwent thyroidectomy had thyroid cancer.