Correlation of sonographic features in nodules with atypia of undetermined significance on FNA report and post operative diagnosis of papillary thyroid carcinoma

Thyroid nodules classified as Bethesda Category III, atypia of undetermined significance (AUS), present a significant clinical challenge due to their indeterminate risk of malignancy. Consequently, many patients undergo diagnostic lobectomy, often for benign disease, which could cause complications such as laryngeal nerve paralysis. This study aimed to evaluate the diagnostic utility of sonographic features, clinical characteristics, and the TI-RADS in predicting Papillary Thyroid Carcinoma (PTC) within this specific cytological subgroup. This retrospective study evaluated 309 adult patients with surgically resected AUS thyroid nodules at referral centers. Preoperative sonographic features, clinical characteristics, and biochemical profiles were analyzed and compared with the final histopathological diagnosis. Multivariable logistic regression and ROC curve analyses were utilized to identify independent predictors of malignancy and assess diagnostic performance. The post-operative malignancy rate was 37.5%. Multivariable analysis identified solid composition (aOR 2.32) and taller-than-wide morphology (aOR 2.28), as independent predictors of malignancy. Notably, nodule size demonstrated an inverse relationship with malignancy ( P < 0.001). Clinical symptoms, specifically dysphagia and hoarseness, were strongly associated with PTC. The ACR TI-RADS classification yielded an AUC of 0.895, demonstrating the strongest diagnostic performance in the study and outperforming the clinical-sonographic model (AUC 0.853). The post-operative malignancy rate among surgically treated AUS nodules is non-negligible and is significantly associated with specific sonographic and clinical profiles. Within this surgically managed cohort, smaller, solid, taller-than-wide nodules with associated compressive symptoms carried a high probability of PTC. In contrast, larger, cystic, or wider-than-tall nodules may be candidates for active surveillance, though these recommendations are drawn from a surgically selected population. Not applicable.