CLINICAL ARTICLE J Neurosurg 129:27–34, 2018 C raniopharyngiomas are intracranial epithelial neo- plasms with an estimated incidence of 0.13 per 100,000 cases per year. A bimodal age distribu- tion, with peaks at 5–14 and 50–74 years, is present, and no difference in incidence by sex has been reported. 5 The tumors may be entirely suprasellar, or they may exhibit in- trasellar involvement. The prominent symptoms in patients diagnosed with craniopharyngioma include visual defcits, endocrine defciencies (such as diabetes insipidus), and headache. 27 As the majority of craniopharyngiomas show benign biological behavior, surgery, via either craniotomy or endoscopy, remains the frst choice for treatment due to its advantages in tumor debulking and intracranial decom- pression. 11 However, craniopharyngiomas arise adjacent to ABBREVIATIONS AUC = area under the curve; FFPE = formalin-fixed and paraffin-embedded; ICA = internal carotid artery; ROC = receiver operating characteristic; WT = wild type. SUBMITTED December 11, 2016. ACCEPTED April 4, 2017. INCLUDE WHEN CITING Published online October 6, 2017; DOI: 10.3171/2017.4.JNS163113. * Drs. Yue and Yu contributed equally to this work. Prediction of BRAF mutation status of craniopharyngioma using magnetic resonance imaging features *Qi Yue, MD, 1 Yang Yu, MD, 2 Zhifeng Shi, MD, 1 Yongfei Wang, MD, PhD, 1 Wei Zhu, MD, PhD, 1 Zunguo Du, MS, 3 Zhenwei Yao, MD, PhD, 2 Liang Chen, MD, PhD, 1 and Ying Mao, MD, PhD 1,4 Departments of 1 Neurosurgery, 2 Radiology, and 3 Pathology, Huashan Hospital, Fudan University; and 4 State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, Shanghai, China OBJECTIVE Treatment with a BRAF mutation inhibitor might shrink otherwise refractory craniopharyngiomas and is a promising preoperative treatment to facilitate tumor resection. The aim of this study was to investigate the noninvasive diagnosis of BRAF-mutated craniopharyngiomas based on MRI characteristics. METHODS Fifty-two patients with pathologically diagnosed craniopharyngioma were included in this study. Polymerase chain reaction was performed on tumor tissue specimens to detect BRAF and CTNNB1 mutations. MRI manifesta- tions—including tumor location, size, shape, and composition; signal intensity of cysts; enhancement pattern; pituitary stalk morphology; and encasement of the internal carotid artery—were analyzed by 2 neuroradiologists blinded to patient identity and clinical characteristics, including BRAF mutation status. Results were compared between the BRAF- mutated and wild-type (WT) groups. Characteristics that were signifcantly more prevalent (p < 0.05) in the BRAF- mutated craniopharyngiomas were defned as diagnostic features. The minimum number of diagnostic features needed to make a diagnosis was determined by analyzing the receiver operating characteristic (ROC) curve. RESULTS Eight of the 52 patients had BRAF-mutated craniopharyngiomas, and the remaining 44 had BRAF WT tu- mors. The clinical characteristics did not differ signifcantly between the 2 groups. Interobserver agreement for MRI data analysis was relatively reliable, with values of Cohen k ranging from 0.65 to 0.97 (p < 0.001). A comparison of fndings in the 2 patient groups showed that BRAF-mutated craniopharyngiomas tended to be suprasellar (p < 0.001), spherical (p = 0.005), predominantly solid (p = 0.003), and homogeneously enhancing (p < 0.001), and that patients with these tumors tended to have a thickened pituitary stalk (p = 0.014). When at least 3 of these 5 features were present, a tumor might be identifed as BRAF mutated with a sensitivity of 1.00 and a specifcity of 0.91. The area under the ROC curve for the sum of all 5 diagnostic criteria was 0.989 (p < 0.001). CONCLUSIONS The BRAF mutation status of craniopharyngiomas might be predicted using certain MRI features with relatively high sensitivity and specifcity, thus offering potential guidance for the preoperative administration of BRAF mutation inhibitors. https://thejns.org/doi/abs/10.3171/2017.4.JNS163113 KEY WORDS craniopharyngioma; BRAF; diagnosis; magnetic resonance imaging; oncology J Neurosurg Volume 129 • July 2018 27 ©AANS 2018, except where prohibited by US copyright law