High grade changes (moderate and severe dyskaryosis)
An abnormal smear report indicates that there are precancerous changes in the cells covering the cervix. Borderline and low grade changes are also tested for high risk HPV, and referred for colposcopy only if positive. High grade changes comprising of moderate and severe dyskaryosis are referred urgently for colposcopic assessment.
Many premalignant and malignant lesions on the cervix have detectable characteristics which can be identified through the colposcope, and biopsies are taken for pathological examination.
Colposcopy is an outpatient procedure performed with the woman lying on her back in lithotomy position. A speculum is inserted to open the vagina to visualise the cervix. The colposcope is a microscope that is placed outside the speculum (and outside the body) which magnifies the image of the cervix. Special dyes are used to paint the cervix to demonstrate any abnormal appearing areas. The dyes commonly used are acetic acid and iodine. It is very important to visualise an area on the cervix called the transformation zone where most of precancerous and cancerous lesions arise.
Areas of the cervix which turn white after the application of acetic acid or have an abnormal vascular pattern are abnormal, and application of iodine helps in highlighting these areas as they do not take the dark brown stain of the iodine. Colposcopic assessment classifies the lesion as low grade and high grade.
After a complete examination, the areas with the highest degree of visible abnormality are defined and biopsies obtained. Most doctors and patients consider anesthesia unnecessary, however, a local anaesthetic may be used to diminish patient discomfort, particularly if more than one biopsy samples are taken. The raw areas after biopsy are cauterised with silver nitrate to control bleeding. Women can expect to have a thin grey discharge for up to several days after the procedure.
Abnormalities on the biopsy samples are then described as:
CIN 1 – one third of the thickness of the lining covering the cervix has abnormal cells
CIN 2 – two thirds of the thickness of the lining covering the cervix has abnormal cells
CIN 3 – the full thickness of the lining covering the cervix has abnormal cells
Without proper treatment, precancerous abnormalities may develop into cancerous lesions. Various treatments exist for significant lesions, the most common being large loop excision of transformation zone (LLETZ). All treatment procedures aim to remove or destroy the abnormal cells.
LLETZ (Large Loop Excision of Transformation Zone) is an outpatient procedure and the patient can go home immediately after the procedure. It involves removing the abnormal cells on the cervix using a thin metal loop through which an electric current is passed- an electrosurgical technique. The procedure is done under local anaesthesia under colposcopic guidance. However for very anxious women or where the procedure is expected to be difficult, the procedure can be done in operating theatres under general anaesthesia.
Appropriate follow-up after treatment is very important. The NHS screening programme recommendations are as follows:
After a biopsy showing CIN1, a cervical smear and HPV testing is done after 1 year; if both negative, the patient returns to routine 3 yearly screening. After LLETZ for CIN 2 or 3, a cervical smear and HPV testing is done after 6 months; if both negative, the patient returns to routine 3 yearly screening.
We can offer women interim cervical smear and HPV testing for reassurance which is not available on NHS.