title: Extraventricular Intraparenchymal Choroid Plexus Tumors in Cerebral Hemisphere: A Series of 6 Cases.
abstract: OBJECTIVE
  Extraventricular intraparenchymal choroid plexus tumors (CPTs) in the cerebral hemisphere are extremely rare. The aim of this study was to investigate the clinical characteristics, radiologic findings, and surgical outcomes of this atypical type of CPT.
  
  
  METHODS
  The study comprised 6 patients with pathologically proven extraventricular intraparenchymal CPTs who were surgically treated at Qilu Hospital of Shandong University. The PubMed database was searched for similar cases published before January 2015, and these cases were reviewed.
  
  
  RESULTS
  Patients were 5 (83.3%) men and 1 (16.7%) woman with an average age of 46.5 years. Symptoms and signs of CPT were usually associated with increased intracranial pressure and invasion of functional areas by tumor. Magnetic resonance imaging commonly demonstrated a contrast-enhancing intraparenchymal mass with cysts; hydrocephalus was not observed in any cases. Subtotal resection and gross total resection were achieved in 1 (16.7%) and 5 (83.3%) cases, respectively. There were 3 cases (50.0%) of choroid plexus papilloma, 2 cases (33.3%) of atypical choroid plexus papilloma, and 1 case (16.7%) not otherwise specified. There was a low incidence of postoperative complications, and surgical outcomes of CPTs were satisfactory.
  
  
  CONCLUSIONS
  In contrast to typical lesions, extraventricular intraparenchymal CPTs in the cerebral hemisphere are rarely associated with hydrocephalus. Magnetic resonance imaging features are key in preoperative diagnosis; nevertheless, it is difficult to distinguish this atypical type of CPT from other lesions. Surgical removal of the tumor is safe and efficacious.
authors.affiliation: Department of Neurosurgery, Qilu Hospital of Shandong University, Shandong, China; Brain Science Research Institute, Shandong University, Shandong, China.
authors.forename: Qichao
authors.initials: Q
authors.lastname: Qi
authors.affiliation: Department of Neurosurgery, Qilu Hospital of Shandong University, Shandong, China.
authors.forename: Shilei
authors.initials: S
authors.lastname: Ni
authors.affiliation: Department of Neurosurgery, Qilu Hospital of Shandong University, Shandong, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Brain Science Research Institute, Shandong University, Shandong, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Huang
authors.affiliation: Department of Neurosurgery, Qilu Hospital of Shandong University, Shandong, China; Brain Science Research Institute, Shandong University, Shandong, China. Electronic address: lixg@sdu.edu.cn.
authors.forename: Xingang
authors.initials: X
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000368:Aged; D054022:Cerebrum / Q000473:pathology / Q000601:surgery; D002648:Child; D002681:China; D016545:Choroid Plexus Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods*; D020288:Papilloma, Choroid Plexus / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: Cerebral hemisphere; Choroid plexus tumors; Extraventricular; Intraparenchymal; Magnetic resonance imaging