First of all you will be seen by friendly staff who are dedicated to this clinic. They will understand how you may be worried and will take time to discuss your smear result before the examination. You will be examined on a purpose-built couch. The cervix is viewed using a speculum (the instrument needed for your smear to be taken) and then examined with the colposcope at low magnification (4-6X). The doctor or nurse will put a number of different solutions on the cervix and look for changes that indicate the presence or otherwise of pre-cancerous changes (or CIN).
8.1 Different techniques used in the colposcopic examination
Acetic acid colposcopy
Acetic acid (dilute vinegar) is applied to the cervix using a cotton wool ball or by a spray. Abnormal areas such as CIN will tend to turn white (acetowhite). The exact reason why CIN tissue turns white with acetic acid is not fully understood. Also it is important to say that some areas of acetowhite do not indicate CIN at all. One of the challenges facing the colposcopist is to decide which areas of acetowhite truly represent pre-malignancy and to avoid treating minor conditions.
Schiller's iodine test
The colposcopist may use another test using an iodine solution. Normal tissue on the outside of the cervix stains dark brown when iodine is applied. On the other hand, pre-cancerous abnormalities may not stain with iodine. This test may be used following acetic acid colposcopy and is often used before treatment.
8.2 Making the diagnosis
Most colposcopists use a combination of the acetic acid and Schiller’s iodine tests. If there is an abnormality the colposcopist should be able to estimate whether it is a likely pre-cancerous abnormality or not according to:
How white the tissue goes after using acetic acid
How quickly the tissue turns white
How smooth or irregular the surface is
The different patterns of the blood vessels (mosaic and punctation) under the surface of the cervix
8.3 Taking a biopsy
To be sure of the diagnosis, a biopsy is often required – this means taking a bigger sample of tissue from the cervix with a special instrument. Depending on the results of this biopsy the colposcopist will decide whether you need treatment.
If it is obvious that you will be likely to need treatment this can be done at the first visit – in this case all of the abnormal area is removed and this constitutes the biopsy.
These possibilities will be mentioned to you in your information leaflet before your clinic appointment and will be discussed with you in clinic. Sometimes taking the biopsy can be uncomfortable but the person performing the colposcopy will warn you before the biopsy is to be taken. Your colposcopy should never be painful and if you happen to be having difficulty you should discuss this with the colposcopist. If necessary the colposcopy could be stopped.
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