Endocrine Abstracts

JOINT1873

Objectives: To evaluate the results of cytology tests performed at our centre, correlate them with ultrasound characteristics and, in cases with surgical indication based on cytology results (Bethesda IV-VI), compare them with final pathological findings.

Patients and Methods: The EU-TIRADS classification was used for ultrasound characteristics, and the Bethesda system was used for cytology results. We analysed the results of 1,236 valid cytology samples recorded in our database from 20 June 2019 to 24 May 2024. Of the 93 nodules classified as Bethesda IV-VI, pathological findings were reviewed for the 87 that underwent surgery.

Results: The distribution of Bethesda categories was as follows: 938 nodules (75.9%) were Bethesda II, 202 (16.3%) Bethesda III, 26 (2.1%) Bethesda IV, 37 (3%) Bethesda V, and 33 (2.7%) Bethesda VI. Among EU-TIRADS 3 nodules, 19 out of 666 (2.9%) were Bethesda IV-VI; among EU-TIRADS 4, 36 out of 576 (6.3%); and among EU-TIRADS 5, 38 out of 257 (14.8%). Malignancy was confirmed in 62 out of 87 (71.3%) surgically treated cases: 5 out of 23 (21.7%) Bethesda IV nodules were malignant, 28 out of 36 (77.8%) Bethesda V nodules, and 32 out of 32 (100%) Bethesda VI nodules. For EU-TIRADS 3, 666 cytology tests were performed, with 5 (0.75%) confirmed malignancies; for EU-TIRADS 4, 576 tests with 25 (4.3%) malignancies; and for EU-TIRADS 5, 36 out of 257 (14%) malignancies.

Conclusions: The results indicate lower-than-expected rates of suspicious cytology and confirmed malignancy. Given the low malignancy rates across all ultrasound risk categories, we believe this may reflect a lower risk of malignancy in our population. The findings also support less aggressive surgical approaches or follow-up for nodules with Bethesda IV cytology in our patients.