title: Impact of NRAS Mutations on the Diagnosis of Follicular Neoplasm of the Thyroid.
abstract: Background. Most patients with a preoperative diagnosis of thyroid follicular neoplasm (FN) undergo diagnostic surgery to determine whether the nodule is benign or malignant. Point mutations at NRAS codon 61 are the most common mutations observed in FN. However, the clinical significance of NRAS mutation remains unclear. Methods. From 2012 to 2013, 123 consecutive patients undergoing thyroidectomy for FN were evaluated prospectively. Molecular analyses for NRAS codon 61 were performed with pyrosequencing. Results. The overall malignancy rate in FN was 48.8% (60/123). Of 123 FNs, 33 (26.8%) were positive for the NRAS mutation. The sensitivity, specificity, positive predictive value, and negative predictive value of a NRAS mutation-positive FN specimen to predict malignancy were 37%, 83%, 67%, and 58%, respectively. Patients with a NRAS-positive FN had a higher malignancy rate in additional thyroid nodules beyond the FN than patients with a NRAS-negative FN. The overall malignancy rate of patients with a NRAS-positive FN was significantly higher than that of patients with a NRAS-negative FN (79% versus 52%; P = 0.008). Conclusions. Determining NRAS mutation status in FN helps to improve the accuracy of thyroid cancer diagnosis and to predict cancer risk in accompanying thyroid nodules.
authors.affiliation: Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea.
authors.forename: Ja-Seong
authors.initials: JS
authors.lastname: Bae
authors.affiliation: Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, 222 Banpodaero, Seocho-gu, Seoul 137-701, Republic of Korea ; Department of Pathology, College of Medicine, Dankook University, Cheonan-si, Chungnam 330-714, Republic of Korea.
authors.forename: Seung Kyu
authors.identifier: 0000-0002-7508-6123
authors.initials: SK
authors.lastname: Choi
authors.affiliation: Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, 222 Banpodaero, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Sora
authors.initials: S
authors.lastname: Jeon
authors.affiliation: Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, 222 Banpodaero, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Yourha
authors.identifier: 0000-0001-7449-3432
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea.
authors.forename: Sohee
authors.identifier: 0000-0003-1559-8853
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, 222 Banpodaero, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Youn Soo
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, 222 Banpodaero, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Chan Kwon
authors.identifier: 0000-0001-6843-3708
authors.initials: CK
authors.lastname: Jung