title: Proliferation index as a prognostic marker in hemangiopericytoma of the head and neck.
abstract: BACKGROUND
  Hemangiopericytoma (HPC) of the head and neck is a rare neoplasm whose biologic behavior is difficult to predict by means of conventional histologic parameters.
  
  
  METHODS
  H & E-stained sections from 12 cases of HPC were reviewed. Proliferation index was assessed using an immunoperoxidase stain for MIB-1 (Ki-67).
  
  
  RESULTS
  The study group consisted of 4 adult men, 5 adult women, and 1 infant male. Necrosis, hypercellularity, and pleomorphism were found in 1, 5, and 6 case(s), respectively. The mitotic index per 10 high power fields varied from 0-1 to 15. Proliferation indices using MIB-1 ranged from 2.6% to 52.5%. Clinical follow-up revealed 3 cases with recurrence all possessing proliferation indices of approximately 10%.
  
  
  CONCLUSIONS
  Standard histomorphologic features may be inadequate predictors of clinical outcome. A proliferation index of 10% or greater may indicate a more aggressive subset of HPC of the head and neck.
authors.affiliation: Department of Pathology, University of Michigan Hospitals, Room 2G332, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109-0054, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Kowalski
authors.forename: A F
authors.initials: AF
authors.lastname: Paulino
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D034961:Antigens, Nuclear; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D006393:Hemangiopericytoma / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D019394:Ki-67 Antigen; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009687:Nuclear Proteins; D011379:Prognosis; D014057:Tomography, X-Ray Computed
chemical_list: D034961:Antigens, Nuclear; D019394:Ki-67 Antigen; D009687:Nuclear Proteins