title: Ki-67 labeling in canine perianal glands neoplasms: a novel approach for immunohistological diagnostic and prognostic.
abstract: BACKGROUND
  The antibody Ki-67 is a reliable and easy tool to accurately assess the growth fraction of neoplasms in humans and animals, and it has been used to predict the clinical outcome. Therefore, the aim of the present study was to investigate the immunohistochemical expression pattern of Ki-67 in normal and neoplastic perianal glands of dogs to evaluate the possible use of this proliferation marker as an ancillary method of perianal tumor diagnosis. We studied 42 cases of perianal gland neoplasms including adenomas (n = 15), epitheliomas (n = 15), and carcinomas (n = 12). As controls, 13 tissue samples from normal perianal glands were used. A Ki-67 index was established by a computer-assisted image analysis and compared with manual counting.
  
  
  RESULTS
  Out of the 42 cases of perianal gland neoplasms, 34 were from males and eight from females. Recurrence was reported in 14 cases, being higher (8/12) in carcinomas. Immunostaining for Ki-67 revealed that the carcinomas showed a higher proliferation rate (9.87%) compared to groups of epitheliomas (2.66%) and adenomas (0.36%). For adenomas and epitheliomas of the perianal glands the computer-assisted counting and the manual counting gave similar results; however, only the computer-assisted image analysis was efficient to predict the perianal gland carcinoma recurrence.
  
  
  CONCLUSIONS
  Since there were significant differences in the number of Ki-67-positive nuclei, this marker proved to be effective in helping the classification of perianal gland neoplasms and to refine the diagnosis criteria, especially in those samples with high variation in morphology/area. Also, higher Ki-67 index is related to recurrence in cases of perianal gland carcinomas. Further, the computer-assisted image analysis proved to be a fast and reliable method to assess the Ki-67 index in perianal gland neoplasms.
authors.affiliation: UNESP – Univ Estadual Paulista, College of Veterinary Medicine Araçatuba, São Paulo, Brazil.
authors.forename: Rodrigo Storti
authors.initials: RS
authors.lastname: Pereira
authors.forename: Augusto
authors.initials: A
authors.lastname: Schweigert
authors.forename: Guilherme
authors.initials: G
authors.lastname: Dias de Melo
authors.forename: Fernando Vissani
authors.initials: FV
authors.lastname: Fernandes
authors.forename: Felipe Augusto Ruiz
authors.initials: FA
authors.lastname: Sueiro
authors.forename: Gisele Fabrino
authors.initials: GF
authors.lastname: Machado
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000276:immunology / Q000378:metabolism / Q000662:veterinary; D000694:Anal Gland Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002277:Carcinoma / Q000175:diagnosis / Q000276:immunology / Q000378:metabolism / Q000662:veterinary; D049109:Cell Proliferation; D004283:Dog Diseases / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D004285:Dogs; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D007091:Image Processing, Computer-Assisted; D019394:Ki-67 Antigen / Q000032:analysis* / Q000096:biosynthesis; D008297:Male; D010481:Perianal Glands / Q000737:chemistry / Q000378:metabolism; D011379:Prognosis
chemical_list: D015415:Biomarkers; D019394:Ki-67 Antigen