Sun C, Wang Q, Guo Q, et al. - Researchers conducted this retrospective study to concentrate on the patterns and risk factors regarding the onset of new nodules in the contralateral lobe among papillary thyroid carcinomas (PTCs) who had received lobectomy using ultrasonography. The sample consisted of 456 patients (the mean age was 40.7 years) who had unilateral thyroid lobectomy at Cancer Hospital, Chinese Academy of Medical Sciences. In order to identify risk factors for new nodules, logistic regression analysis was performed. Data reported that the overall incidence of new nodules was 41.9%. It was noted that 96.3% of new nodules were no greater than 1 cm whereas only 10.5% of those were with high suspicion of malignancy. New nodules were common in the contralateral lobe, but ultrasound features were usually small and benign. It has been found that older age is a risk factor for predicting new nodules. In terms of the incidence of new nodules on the remnant lobe, lobectomy for 1-4 cm PTC was supported.