Endocrine Abstracts

Introduction: The Bethesda System classifies suspicious thyroid nodules or those with a large size after fine-needle aspiration (FNA) depending on the risk of malignancy through its cytology study. Bethesda category 3 (B3) implies atypia of uncertain significance or follicular lesion of undetermined significance. Objectives: To determine the final diagnosis of category B3 nodules and the number of cases in which a second or third FNA results in a conclusive category (B2, B4, B5 or B6).

Methods: Observational retrospective study of patients with thyroid nodules classified as B3, evaluated between January 2012-December 2015 at “Hospital Universitario Reina Sofía” in Córdoba. Results were analysed with SPSS 19.0. Statistical analysis: Student’s t-test to compare means and Chi-squared test/ Fisher’s exact test to compare proportions.

Results: 88 patients, 83% females. Mean age: 52.8±13.9 years old. 65.9% of nodules were suspicious on ultrasonography. Maximum diameter: 29.9±14.1 mm. 22.8% of patients had symptoms related to their nodules, being dysphagia the most prevalent. 61.4% of patients underwent surgical treatment, 55.6% of which were thyroidectomies. Final diagnosis: 15.9% malignant, 45.5% benign and 38.6% unknown. Final diagnosis after surgery: 42.6% adenoma, 21.1% benign follicular nodule, 18.5% papillary carcinoma, 5.6% nodular Hashimoto and 12.2% others. In the 75 nodules firstly classified as B3, a second FNA (performed in 45 patients) was conclusive in 21 patients (46.6%). A third FNA (7 patients) was determinate in 3 of them (42.9%). We didn’t find a statistically significant association between malignant or benign disease with gender, age, symptomatology or size/sonographic features of nodules in our series.

Conclusions: The prevalence of thyroid malignant illness classified as B3 in our study is concordant with the previous published studies, being adenoma the most frequent pathology after thyroidectomy. In nodules firstly categorized as B3, a second or third FNA is determinate in less than half of the cases.