title: Distribution pattern of Ki67 immunoreactivity in ductal intraepithelial neoplasia: Correlation with lesion grade and potential utility.
abstract: BACKGROUND
  In this study, the pattern of distribution of the nuclei immunoreactive with Ki67 was examined in DIN1c (DCIS, grade 1/low grade), DIN2 (DCIS, grade 2/intermediate grade), and DIN3 (DCIS, grade 3/high grade). The lesions were evaluated to determine if distinctive patterns could be identified in correlation with lesion grade.
  
  
  METHODS
  Fifty seven (n=57) consecutive DIN cases were investigated. Of these, 15 qualified as DIN1c, 28 as DIN2 and 14 as DIN3. The patterns of distribution were recorded for each case as either basal/peripheral or haphazard within the epithelial proliferation.
  
  
  RESULTS
  There was a statistically significant difference between the DIN1c, DIN2 and DIN3 in terms of basal/peripheral versus haphazard distribution of Ki67 immunostaining (Chi-square test, P<0.0001). Basal/peripheral staining pattern was dominant among the DIN1c cases, while haphazard staining pattern was the dominant distribution among the DIN3 cases. One half of the DIN2 cases showed basal/peripheral staining pattern, while the other half showed a haphazard staining pattern.
  
  
  CONCLUSIONS
  High grade DIN lesions show haphazard Ki67 staining while low grade DIN lesions show basal/peripheral Ki67 staining in the proliferating epithelial cells. This feature could be practical in separating DIN lesions into low grade (basal/peripheral-Ki67) and high grade (haphazard-Ki67) eliminating the grade 2/intermediate category.
authors: Department of Pathology, Yale University School of Medicine, New Haven, CT, United States of America. Electronic address: ugur.ozerdem@yale.edu.
authors: Ugur
authors: U
authors: Ozerdem
authors: Department of Pathology, Yale University School of Medicine, New Haven, CT, United States of America.
authors: Fattaneh A
authors: FA
authors: Tavassoli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000378:metabolism* / Q000473:pathology; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism*; D008875:Middle Aged; D060787:Neoplasm Grading
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen
keywords: Breast; Cancer; Ductal intraepithelial neoplasia; Ki67