CIN 3: the role of lesion size in invasion

Br J Obstet Gynaecol. 1992 Jul;99(7):583-6. doi: 10.1111/j.1471-0528.1992.tb13825.x.


Objective: To define the relation between the size of a CIN 3 lesion (measured histologically) and invasive squamous carcinoma.

Design: Measurement of CIN 3 by computerized planimetry of histological sections from 39 cone biopsies containing microinvasive cancer. Comparison with previous measurements of CIN lesions, associated with different grades of dyskaryosis.

Results: Microinvasive carcinoma of the cervix is associated with extensive CIN 3 on the surface and in endocervical crypts. The mean size of CIN 3 lesions showing microinvasion is seven times greater than that for severe dyskaryosis without invasion, (P less than 0.0001) and a 100-fold greater than with mild dyskaryosis (P less than 0.00001).

Conclusion: Invasive squamous carcinoma of the cervix arises in large CIN 3 lesions and these are associated usually with severe dyskaryosis. We propose a model for the development of high-grade precancer as a small focus within low grade precancer which then undergoes expansion in size, accompanied by apparent progression in cytological grade.

MeSH terms

  • Biopsy
  • Carcinoma in Situ / pathology*
  • Carcinoma, Squamous Cell / pathology*
  • Cervix Uteri / pathology*
  • Female
  • Humans
  • Neoplasm Invasiveness
  • Precancerous Conditions / pathology*
  • Uterine Cervical Neoplasms / pathology*
  • Vaginal Smears