Atypia of undetermined significance in thyroid fine-needle aspiration cytology: Clinicopathological predictors of malignancy

초록

Background: Fine needle aspiration (FNA) is the gold standard testing modality for benign and malignant thyroid nodules. Categorization as atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) is regarded as diagnostically ambiguous. This study was designed to identify clinical predictors of malignancy in the subset of patients with AUS/FLUS on FNA cytology. Methods: Retrospective study was done on 150 patients who underwent thyroidectomy after initial diagnosis of AUS/FLUS on preoperative FNA cytology between January 2010 and January 2017. All patients underwent total or subtotal thyroidectomy without repeat FNA biopsy or additional diagnostic modality. Results: Among 150 patients, 84 (56%) were confirmed as malignant nodule after surgery. We identified that the presence of preoperative ultrasonographic multifocality (odds ratio [OR] 1.181; 95% confidence interval [CI] 0.495–2.817, p < 0.01) and sonographic suspicion of malignancy (OR 18.622; 95% CI 4.666–74.315, p < 0.01).were shown to be significantly related to malignancy, whereas feature of thyroiditis on preoperative sonogram was associated with a reduced risk of malignancy (OR 0.144; 95% CI 0.046-0.451, p < 0.01). Conclusions: We recommend that surgical resection of thyroid nodules may be considered in patients with AUS/FLUS showing sonographically suspicious of malignancy and those with multiple nodules.