Diagnostic standards

lead colp

Summary of diagnostic standards

Diagnostic standards

At the colposcopy examination the following data must be recorded (100%)

  • Reason for referral 
  • Grade of cytological abnormality 
  • Whether the examination was adequate - was the entire cervix  seen
  • The presence or absence of vaginal and/or endocervical extension 
  • The colposcopic features of any lesion 
  • The colposcopic impression
  • The type of transformation zone, ie type 1,2 or 3
  • The site of any colposcopically directed biopsies

An excisional form of biopsy is recommended (95%)

  • When most of the ectocervix is replaced with high-grade abnormality 
  • When low-grade colposcopic change is associated with high-grade dyskaryosis (severe) or worse
  • When a lesion extends into the canal – sufficient canal must be removed with endocervical extension of the abnormality

Reasons for not performing a biopsy must be recorded (100%).

All women must have had a histological diagnosis established before destructive therapy (100%).

Unless an excisional treatment is planned, biopsy should be carried out when cytology indicates moderate dyskaryosis or worse, and always when a recognisable atypical transformation zone is present (100%). Pregnancy is an exception.

Of all biopsies taken (directed and excisional) more than 90% should be suitable for histological interpretation.

If colposcopically directed biopsy is reported as inadequate for histological interpretation, it should be repeated if there is a residual colposcopic lesion (95%).

For those with an adequate colposcopic examination and the entire squamo-columnar junction and entire lesion visualised, the predictive value of a colposcopic diagnosis of a high- grade lesion (CIN2 or worse) should be at least 65%.