It is done in those with positive cervical cytology for malignant cells or suspicious cells but clinically normal looking cervix, needs to be subjected to colposopic inspection. No vaginal examination should be done prior to colposcope study.

Indications for colposcopy

• To inspect the cervix and vagina in a woman with an atypical papa smear.
• To select the area showing atypical colposcopic appearance for a colposcopic directed biopsy.
• To ensure that the vaginal margins are clearly defined while undertaking conization or locally destructive surgery.
• To evaluate lesions of the vagina and vulva.
• During conservative treatment of CIN cervix like cryosurgery and laser vaporization to ensure that the entire lesion is destroyed.
• Follow up patients treated conservatively for CIN.

Procedure

The patient is put in lithotomy position and the cervix exposed with a speculum. The mucus over the cervix is swabbed with saline and 5% acetic acid applied over the cervix. The cellular and vascular patterns over the cervix and the vagina are studied. Mosaic pattern, punctuations and leukoplakia are the abnormalities noted and are biopsied.

CIN lesions reveal as aceto-white areas with clear margins. Mosaic and punctuated points over the white background also suggest CIN lesion.

Invasive cancer displays large vessels which may be corkscrew or comma shaped running a bizarre course.