A B C D E F G H I J K L M N O P R S T U V W

CERVICAL CYTOLOGY - COLPOSCOPY

A Background to Cervical Cytology

The cervix is the lower part of the womb, which protrudes into the top of the vagina. It is made of tough fibrous tissue, and is shaped like a tube. A narrow canal runs through the cervix which opens into the cavity of the womb. The lower end of this canal is called the external os; the upper end is called the internal os. It is this canal through which the sperm must swim to reach the womb, and then into the tube in order to fertilize the egg. The skin of the vagina is the same as the tough skin on the surface of the body. It covers the surface of the cervix, but at the external os it changes its nature: in the canal, the lining skin is much more velvety and delicate. The place where these two types of skin meet is where most cancers of the cervix start. Before these cancers actually develop, changes in the cells can often be detected. The changes may indicate the possibility of future cancer. There are two ways in which these cells can be studied to detect possible pre-cancerous changes. One is by doing a smear test: the other is by a procedure called colposcopy

The smear test (PAP smear)

A smear test should be done at least every 3 years after the age of 20 until the age of 65 on all women who are or have been sexually active. It is not necessary if the womb has been removed, unless recommended by your doctor. It is not done during a period. It involves a simple internal examination with an instrument called a speculum. It is essential that the doctor sees the area which is at risk clearly. A small plastic or wooden instrument called a spatula is used to gently scrape some cells from this area. They are then smeared on to a glass slide and sent to the laboratory. An internal examination is a little embarrassing but a smear should not be painful or otherwise unpleasant. The result of the smear will take a few weeks. If urgent, however, the result can be obtained in a few days.

The result of the smear

NORMAL

Most smears are negative. If this is the case, it does not need repeating for 3 years. If there have been previous abnormal smears, the doctor might suggest an earlier repeat.

INADEQUATE

Sometimes the number of cells obtained from the smear may be insufficient for an adequate examination. The laboratory may then request that the smear is repeated. The test may also need to be repeated if there is bleeding when the smear is taken. A repeat smear is usually done after 3 months. If three smears in row are inadequate a further examination called a colposcopy will be recommended (see below) This is done to check that the cervix is normal.

INFLAMMATION

Quite often the laboratory asks for the smear to be repeated because the cells show inflammation. This should not cause worry to the patient: the explanation is simple. It means that the cells are distorted by the changes of inflammation or slight infection. These changes make the cells impossible for the laboratory to analyse. It is for this reason they want a repeat and not because of any question of pre-cancer. Sometimes a course of treatment may be suggested before repeating the smear after 3 months. This is to treat the inflammation. If three smear tests in a row have inflammatory changes a colposcopy will be recommended.

BORDERLINE (BORDERLINE NUCLEAR ABNORMALITIES, BNA)

This means there are changes in some of the cells on the smear slide but not enough to be called definitely abnormal (or dyskaryosis). These changes will often disappear without any treatment but a repeat smear will be arranged after 6 months (instead of the normal 3 years) and if this is still abnormal an appointment arranged for colposcopy.

POSITIVE (DYSKARYOSIS)

A positive smear does not usually mean cancer. It means only the possibility of cancer developing in the future. Dyskaryosis refers to the type of change in the cell. These may be mild, moderate or severe. Smears are often reported as showing dyskaryosis, "suggesting CIN 1, 2, or 3". These are codes which describe how deeply these changes penetrate into the skin of the cervix. CIN 1 is the mildest change. Up to half of cases of CIN1 will get better without any treatment These sorts of changes are often associated with wart virus infections. If the severest form of change (CIN3) is present there is about a one in three chance of cancer developing if nothing further is done. It is not possible to fully assess the severity and depth of the changes just by a smear test. For this, more tissue (not just a few cells) needs to be obtained. The patient is therefore advised to have colposcopy if the smear test is positive. Some smear tests may indicate that the abnormal cells are in the canal of the cervix instead of on the surface or (rarely) that cancer is already present.

Colposcopy

This is done on a special couch with the patient's legs being supported. Otherwise there are no differences from an ordinary examination. The doctor, however, examines the cervix through a microscope called a colposcope. The magnification gives a much better idea of the severity of the changes in the cells. The doctor may apply some clear solution of very dilute Acetic acid or a brown iodine solution to help identify any abnormal cells. If the colposcopy confirms the abnormal changes, the doctor may remove some very small pieces of tissue for closer examination. This is called a biopsy. This may cause brief discomfort, but should not be painful. Sometimes the changes in the cells reach further up the canal in the cervix. The upper margin of the abnormal cells cannot then be seen. The doctor will then suggest admission to hospital for an anaesthetic to allow access to this tissue.

Treatment

If the colposcopy shows that the abnormal cells are all confined to surface skin of the cervix, treatment may be given to you immediately or a few weeks later after the results of any biopsies are known. This treatment will be to destroy the cells of the affected and surrounding areas completely. The treatment may be done by Laser, freezing or an electric cutting wire loop (LETZ). Only a local anaesthetic is necessary and this can be injected directly into the cervix itself. These treatments are very safe. It is important that doctor knows if there is any chance that you might be pregnant. If you are already pregnant he may decide to postpone treatment until after the pregnancy. If the colposcopy suggests that the cell changes may extend deeper into the skin, the treatment may be different. It will mean admission to hospital, an anaesthetic and removal of part of the cervix. This operation is called a cone biopsy. If this shows that the changes are only on the surface, then no further treatment is needed. Although these treatments are very effective in about 1 in every 20 women the abnormal cells will persist or return and further treatment be required. For this reason it is essential that all women treated have regular follow-up smears.

After treatment

You may get a period like pain during the first day after treatment and this can be treated with simple pain killers. A discharge is quite common for a few days after treatment as the cervix heals. You should avoid using tampons and not have intercourse for 4 weeks after treatment. A small number of women may get bleeding from the cervix afterwards. This will normally be due to slight infection and can be treated with antibiotics, although your doctor may recommend returning to the hospital if this happens. Laser, freezing and wire loop treatments should not prevent you getting pregnant in future or giving birth normally.

Future Follow-up

It is vital that any woman who has had an abnormal smear has frequent, regular smears. How frequent and for how long will vary from patient to patient. After treatment a woman will usually be asked to have 2 follow up smear in the first year and a further smear every 12 months for another 4 years. If these smears are all normal she can then go back to having a smear test every three years. All women must follow the instructions they are given for future smears. If they are not given clear instructions, they must ask. Having regular smear tests and treatment if abnormalities are found reduces the chances of getting cancer of the cervix by almost three quarters.