title: Atypical choroid plexus papilloma: clinicopathological and neuroradiological features.
abstract: Background Atypical choroid plexus papilloma (APP) is a rare, newly introduced entity with intermediate characteristics. To date, few reports have revealed the magnetic resonance (MR) findings. Purpose To analyze the clinicopathological and MR features of APP. Material and Methods The clinicopathological data and preoperative MR images of six patients with pathologically proven APP were retrospectively reviewed. The MR features including tumor location, contour, signal intensity, degree of enhancement, intratumoral cysts, and necrosis; and flow voids, borders, peritumoral edema, and associated hydrocephalus were analyzed. Results The APP were located in the ventricle (n = 4) and cerebellopontine angle (CPA, n = 2). Tumor dissemination along the spinal subarachnoid space was found in one patient. The tumors appeared as milt-lobulated (n = 5) or round mass (n = 1), with slightly heterogeneous signals (n = 5) or mixed signals (n = 1) on T1-weighted and T2-weighted images. Heterogeneous and strong enhancement were found in five cases on contrast-enhanced images. Three of four intraventricular tumors had a partly blurred border with ventricle wall. Four tumors had mild to moderate extent of surrounding edema signals. A slight hydrocephalus was seen in four patients. Incomplete capsule was seen in four tumors at surgery. Histopathologically, mild nuclear atypia was seen in all tumors with a mitotic rate of 2-5 per 10 high-power fields. Conclusion APP should be included in the differential diagnosis when an intraventricular or CPA tumor appearing as a multi-lobulated solid mass with slight heterogeneity, heterogeneous strong enhancement, partly blurred borders, mild to moderate peritumoral edema, or slight hydrocephalus are present.
authors.affiliation: 1 Department of Medical Imaging, Huai'an First People's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Yu-Zhen
authors.initials: YZ
authors.lastname: Shi
authors.affiliation: 1 Department of Medical Imaging, Huai'an First People's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Mao-Zhen
authors.initials: MZ
authors.lastname: Chen
authors.affiliation: 1 Department of Medical Imaging, Huai'an First People's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: 1 Department of Medical Imaging, Huai'an First People's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Guo
authors.affiliation: 2 Department of Radiology, Affiliated Hospital of Nanjing University of Traditional Chinese Medicine (TCM), Jiangsu, PR China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.affiliation: 1 Department of Medical Imaging, Huai'an First People's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Kong
authors.affiliation: 1 Department of Medical Imaging, Huai'an First People's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Zhuang
authors.affiliation: 1 Department of Medical Imaging, Huai'an First People's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Xu
authors.affiliation: 3 Department of Pathology, Huai'an First Peopler's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Rui-Rui
authors.initials: RR
authors.lastname: Zhang
authors.affiliation: 1 Department of Medical Imaging, Huai'an First People's Hospital, Nanjing Medical University, Jiangsu, PR China.
authors.forename: Gen-Ji
authors.initials: GJ
authors.lastname: Bo
authors.affiliation: 2 Department of Radiology, Affiliated Hospital of Nanjing University of Traditional Chinese Medicine (TCM), Jiangsu, PR China.
authors.forename: Zhong-Qiu
authors.initials: ZQ
authors.lastname: Wang
mesh_terms: D000328:Adult; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D020288:Papilloma, Choroid Plexus / Q000000981:diagnostic imaging* / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Choroid plexus tumors; atypical choroid plexus papillomas; contrast medium; magnetic resonance imaging (MRI); spectroscopy