Surgical approach preferences and malignancy rates in patients with cytologically bethesda category III and IV thyroid nodules

Aim: This study aimed to evaluate surgical approach preferences and malignancy rates in patients who underwent thyroid fine needle aspiration biopsy (FNAB) and were found to have Bethasda category III and IV thyroid nodules. Material and Methods: According to the FNAB results, the data of a total of 172 patients with Bethesda Category III (atypia of undetermined significance (AUS)) and IV (suspicious follicular neoplasia (FNS)) thyroid nodules and who underwent surgical treatment were evaluated retrospectively. The patients demographic data, ultrasonography data, surgical methods applied to the patients, and postoperative histopathology results were examined. Results: A total of 172 patients, 121 women (70.3%) and 51 men (29.6%), were included in the study. The average age of the patients was found to be 49.1 ± 13.2 years. According to the FNAB results of the patients, 155 patients were operated on AUS and 17 patients were operated on FNS. Malignancy was detected in 69 (45.5%) of 155 patients with AUS and in 10 (58.8%) of 17 patients with FNS. Following FNAB, total thyroidectomy was performed in 136 (79%) of all patients, lobectomy was performed in 36 (21%) patients, and completion thyroidectomy was performed in 13 (36%) of the patients who underwent lobectomy. Total thyroidectomy was performed in 124 (80%) of the patients operated on due to AUS, while lobectomy was performed in 31 (20%) patients. Of the 17 patients with FNS, 12 (70.6%) patients were treated with total thyroidectomy and 5 (29.4%) patients with lobectomy. Lobectomy could have been an adequate surgical treatment in 70 patients who underwent total thyroidectomy and no malignancy was observed, and in 20 patients in whom the tumor was unilateral even though malignancy was detected and no lymphovascular or capsule invasion was observed in the tumor (90 of 172 patients (52.3%) in total). Conclusion: Our study showed that malignancy rates are not low in patients diagnosed with AUS and FNS. Our study indicates that total thyroidectomy is preferred in patients diagnosed with AUS and FNS, contrary to current recommendations. In patients whose FNAB result is reported as AUS or FNS, especially in patients with a solid nodule in a single lobe, lobectomy and isthmectomy should be recommended surgical treatment approaches, and if necessary, complementary thyroidectomy should be recommended according to the results of histopathological examination in the postoperative period.