title: CNS Hemangiopericytoma: A Systematic Review of 523 Patients.
abstract: BACKGROUND
  Central nervous system (CNS) hemangiopericytomas are rare mesenchymal tumors of the brain. In the absence of randomized clinical trials or large studies, the only information we have about the natural history and the management is from isolated clinical case series. They have suggested that surgery is beneficial, with conflicting results on the role of complete resection and adjuvant radiation. We have conducted a systematic review of clinical case series of CNS hemangiopericytoma analyzing the biology of the tumor and the best follow-up and management strategy.
  
  
  METHODS
  Fifteen pertinent clinical case series on newly diagnosed CNS hemangiopericytoma were selected by a review of literature. A total of 523 patients were analyzed for age, sex, mode of recurrence and metastases, and survival after complete/incomplete resection with or without radiation.
  
  
  RESULTS
  The mean age was found to be 44.17 (±3.59) years. The incidence was higher in male individuals younger than 45 years and in older female individuals. Complete resection and adjuvant radiation significantly improved survival in comparison with incomplete resection and no radiation, respectively (P<0.0001). Furthermore, a significant trend of the tumor to recur locally compared with extraneural and neural axis metastases was noted (P<0.0001). The mean time for distant metastases was seen to be 91.33 (±12.66) months.
  
  
  CONCLUSIONS
  Complete resection followed by adjuvant radiation improves survival. Extraneural metastases, especially to lung, bone, and liver, are not uncommon and can occur late in the disease course for which continued follow-up is required. There is also a need to establish a systemic treatment regimen to control the distant metastases.
authors.affiliation: Departments of *Hematology/Oncology, University of Cincinnati ‡Department of Medicine, Good Samaritan Hospital, Cincinnati, OH †Department/School of Chemical and Bio Technology, SASTRA University, Thanjavur, Tamil Nadu, India.
authors.forename: Abhimanyu
authors.initials: A
authors.lastname: Ghose
authors.forename: Gunjan
authors.initials: G
authors.lastname: Guha
authors.forename: Ria
authors.initials: R
authors.lastname: Kundu
authors.forename: John
authors.initials: J
authors.lastname: Tew
authors.forename: Rekha
authors.initials: R
authors.lastname: Chaudhary
mesh_terms: D000008:Abdominal Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D000328:Adult; D000367:Age Factors; D016543:Central Nervous System Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D006393:Hemangiopericytoma / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D018365:Neoplasm, Residual; D018714:Radiotherapy, Adjuvant; D012737:Sex Factors; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D055815:Young Adult