title: An intraventricular meningioma and recurrent astrocytoma collision tumor: a case report and literature review.
abstract: BACKGROUND
  Intracranial meningioma and glioma collision tumors are relatively uncommon and are even more rarely located within the ventricles.
  
  
  METHODS
  Here, we report a case of a patient with an intraventricular meningioma and astrocytoma collision tumor. A 39-year-old man previously underwent excision of an astrocytoma in the triangle area of the lateral ventricle and exhibited good post-surgery recovery. The astrocytoma recurred in situ six years after the surgery, and the case was complicated by a malignant meningioma. The patient recovered well after surgery to treat the recurrence and was administered radiotherapy after discharge. In addition to reporting on this case, we conducted a literature review of collision tumors; based on this review, we propose several hypotheses regarding the formation of collision tumors.
  
  
  CONCLUSIONS
  We conclude that a possible cause of the collision tumor formation between the intracranial meningioma and the astrocytoma was the recurrence of an astrocytoma-induced malignancy of the arachnoid cells in the choroid plexus.
authors.affiliation: Department of Surgery, First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, 130021, China. 56773130@qq.com.
authors.forename: Duoduo
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, 130021, China. jinluyu@yeah.net.
authors.forename: Jinlu
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Neurosurgery, First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, 130021, China. guoyunbao@jlu.edu.cn.
authors.forename: Yunbao
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Department of Intensive Care Unit, First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, 130021, China. zhaoshujie@jlu.edu.cn.
authors.forename: Shujie
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Department of Surgery, First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, 130021, China. 859258292@qq.com.
authors.forename: Guoguang
authors.initials: G
authors.lastname: Shao
authors.affiliation: Department of Neurosurgery, First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, 130021, China. jinluyu@hotmail.com.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Huang
mesh_terms: D000328:Adult; D001254:Astrocytoma / Q000150:complications* / Q000473:pathology / Q000601:surgery; D001932:Brain Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery; D002551:Cerebral Ventricle Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery; D008579:Meningioma / Q000150:complications* / Q000473:pathology / Q000601:surgery; D009364:Neoplasm Recurrence, Local / Q000209:etiology* / Q000473:pathology / Q000532:radiotherapy; D011379:Prognosis