Endocrine Abstracts

Introduction: Thyroid nodules are very common in the general population (20–75% ultrasound). There are clinical management criteria established by international societies and standardized cytological diagnostic criteria (Bethesda). However, there is still uncertainty in the management of category 3 (follicular lesion of undetermined significance). Objectives: To evaluate the clinical attitude to the cytological diagnosis of Bethesda category 3 (B3) in thyroid fine-needle aspiration cytology (FNA).

Material and methods: Retrospective study of thyroid nodules classified as B3 after FNA referred to our hospital between 2012 and 2018. Statistical analysis: SPSS vs 22.0 (Student’s t-test to compare means and Chi-square/Fisher’s test for proportions).

Results: Two hundred two patients (80.7% female); mean (s.d.) age, 53.5 (13.7) years. 151 nodules underwent a second FNA, with diagnosis B1 12.4%, B2 24.2%, B3 45.8%, B4 (13.1%), B5 (2%) and B6 (1.3%), 4 are pending a second FNA. Forty (40) patients underwent surgery. The remaining 7 were managed (in accordance with patient preferences) with active surveillance alone. After the second FNA, 71.6% patients underwent surgery and 2 (1.3%) were waiting for a third FNA. In 41 cases (27.2%) surgery was ruled out because the 2nd FNA was B2 or by patient preference (B3 in both FNA). Eigteen (8.9%) lesions met the reference-standard criteria for malignancy: 13 papillary thyroid cancers, 4 follicular thyroid cancer, 1 thyroid metastases from other malignancies. The rest: 45.8% (60) follicular adenoma, 11.5% (15) multinodular goiter, 8.1% (11) non-invasive follicular neoplasm with nuclear alterations of papillary carcinoma, 3.1% (4) well-differentiated follicular tumor, 2.3% (3) papillary thyroid microcarcinoma.

Conclusions: The percentage of patients with malignant processes of our series corresponds to the bibliography. Although the use of this category seems correct, the clinical attitude is erratic and surgical over-treatment of hyperplasias occurs. In our series, the second FNA, only recodes 24.2% of the cases as benign, being in practically half of the cases (45.8%) B3 again.