title: Labeling index in pituitary adenomas evaluated by means of MIB-1: is there a prognostic role? A critical review.
abstract: OBJECTIVE
  The present article presents an overview of the literature, and analyses the methods and the primary questions related to assessment of proliferation index using the Ki-67/MIB-1 labeling index in pituitary adenomas. Although atypical adenomas are characterized by their atypical morphological features by an elevated mitotic index, a Ki-67 (MIB-1) labeling index greater than 3% and extensive nuclear staining for p53, use of the proliferation index (LI) of pituitary adenomas in assessing the degree of tumor aggressiveness is a controversial topic in the literature, and there are disparate results involving many studies.
  
  
  METHODS
  A review of literature was carried out to correlate the role of Ki-67 LI and its correlation with clinical findings, tumor size, invasiveness, recurrence, adenoma subtype, adenoma doubling time, and pituitary carcinomas is addressed.
  
  
  RESULTS
  The prognosis cannot be predicted on the basis of the Ki-67 LI alone. Although there is no direct relation between Ki-67 LI and some of these variables and controversial data were found regarding some topics, our review justify the use of Ki-67 in the analysis of pituitary adenomas as an additional information for clinical decision.
  
  
  CONCLUSIONS
  Although assessment of proliferative may be helpful in predicting subsequent tumor recurrence or invasiveness, there are many other important and as yet unidentified factors pituitary tumors. It is clear that further research is needed to clarify these molecular mechanisms to predict those with a potentially poor clinical outcome.
authors.affiliation: Department of Neurology, São Paulo Medical School, State University of São Paulo, Brazil. phpaneurocir@gmail.com
authors.forename: Paulo Henrique Pires
authors.initials: PH
authors.lastname: de Aguiar
authors.forename: Rogério
authors.initials: R
authors.lastname: Aires
authors.forename: Edward R
authors.initials: ER
authors.lastname: Laws
authors.forename: Gustavo Rassier
authors.initials: GR
authors.lastname: Isolan
authors.forename: Angela
authors.initials: A
authors.lastname: Logullo
authors.forename: Chirag
authors.initials: C
authors.lastname: Patil
authors.forename: Laurence
authors.initials: L
authors.lastname: Katznelson
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*; D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor / Q000378:metabolism*; D049109:Cell Proliferation; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008940:Mitotic Index / Q000379:methods; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000473:pathology; D010911:Pituitary Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*; D011379:Prognosis
chemical_list: D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; C440408:MIB-1 antibody