Home Diseases Cervical Intraepithelial Neoplasia (CIN)

Cervical Intraepithelial Neoplasia (CIN)

by Josephine Andrews
Published: Last Updated on 149 views

Doctors refer to cell changes in the cervix as cervical intraepithelial neoplasia (CIN). They are considered a precursor to cervical cancer. The doctor makes the diagnosis of CIN by examining a tissue sample from the cervix. Read here whether CIN can regress and when treatment is necessary.

ICD codes for this disease:

ICD codes are internationally valid codes for medical diagnoses. They can be found, for example, in doctor’s letters or on certificates of incapacity for work.


quick overview

  • What is Cervical Intraepithelial Neoplasia (CIN)? Cell changes in the cervix , precursor of cervical cancer
  • History: Can regress. With CIN I and II, you can wait, with CIN III, surgery is usually performed immediately (conization)
  • Symptoms: CIN causes no symptoms
  • Causes: Chronic infection with human papillomaviruses, especially with high-risk virus types HPV 16 and 18
  • Risk factors: Frequently changing sexual partners, concomitant infection with herpes viruses or chlamydia, smoking, immune deficiency
  • Diagnostics: PAP smear, vaginal reflection, removal of a tissue sample ( biopsy ), HPV test
  • Treatment: Regular check-ups, anti-inflammatory drugs if necessary, surgery (conization)
  • Prevention: HPV vaccination, regular check-ups at the gynecologist

What is Cervical Intraepithelial Neoplasia (CIN)?

CIN is the abbreviation for “cervical intraepithelial neoplasia”. Doctors use this to describe superficial cell changes in the cervix that, if left untreated, may develop into cervical cancer.

The cause of the cell changes is a chronic infection with human papilloma viruses (HPV). HP viruses are very common, almost every woman will be infected with them at some point in her life. Transmission occurs through sexual intercourse.

HPV infections often go away on their own. However, if they persist, they can damage the cells lining the cervix. Under certain circumstances, these initially develop into precursors of cervical cancer (precancerous lesions, CIN) and only later on into cancer. Cervical cancer is the third most common form of cancer in women worldwide.

A diagnosis of CIN does not automatically mean that you will develop cancer. Some CIN resolve on their own. Whether and how CIN is treated depends on the extent of the cell changes (dysplasia).

Distinction between CIN 1, 2 and 3

Physicians divide cervical intraepithelial neoplasia into three degrees of severity:

  • CIN I (CIN 1): low grade dysplasia

CIN I involves slight cell changes that heal on their own in more than half of the women.

  • CIN II (CIN 2): moderate dysplasia

CIN II describes a moderate form of cell change. It regresses on its own in a third of the women affected.

  • CIN III (CIN 3): high grade dysplasia (invasive squamous cell carcinoma)

In CIN III, the cell changes are already well advanced. The changes are still limited to the upper layers of tissue (carcinoma in situ, CIS), but could progress to carcinoma. Since CIN IIl only regresses on its own in very few women, doctors usually advise surgery immediately if this is found.

Can a CIN regress?

If the doctor finds a cervical intraepithelial neoplasia (dysplasia of the cervix), this is not yet a cause for concern. The cell changes grow superficially and may regress again. The likelihood of CIN going away on its own depends on the extent and duration of the infection. As a rule of thumb, the longer an infection with high-risk HPV virus types (HPV 16 and 18) has persisted, the less likely it is to regress and the higher the likelihood of cervical cancer.

CIN I heals spontaneously and without treatment in 60 percent of cases. In 30 percent of cases, the cell changes remain. Here the doctor checks the cervix once a year during the gynecological check-up. 10 percent of all CIN I cases progress to CIN III over many years. If CIN I is present, the doctor checks every three months whether the cell changes are regressing. If CIN I lasts longer than two years, doctors recommend an operation (conization).

In the case of CIN II, 40 percent heal on their own within two years, another 40 percent persist and in 20 percent of the cases CIN III develops from this. A CIN II does not have to be treated immediately. However, the doctor does a Pap test (microscopic examination of a smear from the cervix) and a smear test every three months to monitor how CIN II is developing. If the cell changes have not disappeared after a year, doctors usually recommend an operation (conization).

If the doctor diagnoses CIN III, the chances of the cell changes regressing are only 33 percent. With this finding, it is very likely that the dysplasia will progress to cervical cancer. Because of this, doctors recommend immediate surgery at this stage.

How do you recognize a CIN?

Cervical intraepithelial neoplasia usually causes no symptoms. They are therefore usually only discovered by chance – during the annual check-up at the gynecologist.

Diseases of the genital tract often do not cause any clear symptoms. Pain or itching in the vagina or bleeding (outside the menstrual period) should therefore always be taken seriously. Contact your gynecologist if you notice any abnormalities. He clarifies the cause and decides whether and which treatment makes sense.

What Causes Cervical Intraepithelial Neoplasia?

CIN develops from human papillomavirus (HPV) infection. It is the most common disease transmitted by HPV worldwide. Genital HP viruses are transmitted during sexual intercourse and penetrate the mucous membranes.

Most women will become infected with HPV at some point in their lives, but only a few will develop CIN. In 80 percent of cases, the infection clears up on its own within one to two years without causing any symptoms.

If the immune system is unable to fight off the infection, the cells in the cervix can be damaged by the HPV infection in such a way that precancerous lesions develop. However, it takes about five to ten years for a persistent HPV infection to actually develop into cancer.

Risk Factors High-risk HP virus type

Most HPV infections are harmless and are successfully fought off by the immune system. However, the risk of developing the disease is particularly high if so-called high-risk HPV types (HPV 16 and 18) colonize the cervix. These are virus types that can potentially cause cancer there by triggering precursors of cervical cancer (precancerous lesions). However, it is also possible for infections with high-risk HPV types to heal without treatment.

Other risk factors for genital HPV infection

In addition to infection with the high-risk types HPV 16 and 18, other factors increase the risk of CIN:

  • Frequently changing sexual partners: HP viruses are mainly transmitted during sexual intercourse. The risk of HPV infection increases with the number of sexual contacts. Condoms only provide limited protection because they do not cover all areas of the skin through which the virus is transmitted.
  • Smoking: Smoking not only promotes the development of cancer, but also an infection with HPV. Nicotine accumulates in the mucous membrane of the cervix and thus weakens its defense function.
  • Birth at a young age: For mothers, the risk of infection depends on the age at the birth of the first child and the number of children. During pregnancy, the lining of the cervix changes, making it more susceptible to infections. So a woman who gave birth at 20 is at greater risk than a mother who gave birth to her first child at 35.
  • Immune deficiency: People with a weakened immune system – such as HIV patients or the chronically ill – are less able to ward off infections than healthy people.
  • Infections with other sexually transmitted pathogens: Herpes or chlamydia infections promote infection with HPV viruses.
  • Oral contraceptives: Women who have been on thepill for more than five years have a higher risk of contracting HPV.

How is CIN diagnosed?

Cell changes in the area of ​​the cervix do not cause noticeable symptoms. The gynecologist routinely checks whether such changes are present during the annual check-up.

PAP test

In order to be able to detect cell changes in the cervix, the doctor carries out a so-called PAP test. He takes a smear from the area of ​​the cervix with a cotton swab. This is then examined in a specialized laboratory for changes in the cells.

What does the result of the PAP test say?

PAP I: Normal, healthy cells, no indication of changes, next check-up in a year

PAP II: Slight cell changes (such as a harmless inflammation or a fungal infection), no suspicion of precancerous lesions or cancer, next check-up in a year

PAP III: Unclear findings, more pronounced inflammation or cell changes, further investigations necessary

PAP IIID: There are cell changes (dysplasia), but no cancer. Further investigations are necessary.

PAP IV: Pre-cancerous, early-stage cancer or cancer is present. Further investigations are needed to clarify this.

PAP V: Detection of malignant tumor cells, cancer is very likely.

The procedure depends on the PAP findings

With PAP I and II there is no further need for action, the next smear will be taken at the preventive check-up in a year. From PAP III, further examinations such as a vaginal endoscopy and/or an HPV test are necessary.

vaginal reflection

If the result of the PAP test is PAP III or more, the doctor will perform a colposcopy. He uses a special microscope and an attached camera to examine the mucous membrane of the cervix for changes. If there are any abnormalities, the doctor takes small tissue samples from the cervix (biopsy) with small forceps. These are then sent to a laboratory and examined under a microscope.

The removal of the tissue samples can cause slight pain, but usually only takes a short time. There may be slight bleeding until the wounds on the cervix have healed. It is therefore advisable to use panty liners in the days that follow.

HPV test

The HPV test determines whether an infection with HPV viruses is present. The procedure is similar to that of the PAP test: the doctor removes cells from the cervix with a brush. Some women find the examination uncomfortable and slightly painful.

The cells are then examined in the laboratory. It is determined whether an infection with HP viruses is present at all and what type of virus it is:

  • High-risk virus types: mainly HPV 16 and 18, but also HPV 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59
  • Low-risk virus types: mainly HPV 6 and 11, but also HPV 40, 42, 43, 44, 54, 61, 62, 70, 71, 72, 74, 81 and 83

The HPV test is also used after conization. The doctor checks whether the virus is still present after the operation. If so, the risk of cell changes recurring is increased.

How is CIN treated?

Treatment of CIN I

CIN I heals on its own in around half of women. If there are any signs of inflammation caused by bacteria or fungi, the doctor will treat them with appropriate medication. The next check-up at the gynecologist will be in six months. If the HPV test is positive, another vaginal endoscopy follows and, if necessary, a biopsy.

Treatment of CIN II

CIN 2 does not need immediate treatment. As a rule, it is sufficient to wait and see how the cell changes have developed with a smear test after six months. If CIN II is still present after two years, doctors recommend surgical removal of the change (conization).

Treatment of CIN III

In the case of CIN III, ie advanced stages of cancer, doctors recommend immediate removal by conization.

What is a conization?

During a conization, the doctor removes the diseased tissue from the cervix. The operation is performed under general or local anesthesia. For removal, the doctor uses an electric heating loop (LEEP coning) or a laser and removes a cone-shaped piece of tissue from the cervix. In most women, conization leads to complete healing.

There may be some bleeding after the procedure, but it is usually lighter than a menstrual period. Bleeding can occur again on the eighth to tenth day, when the scab comes off.

Avoid sexual intercourse, baths and tampons for the first three to four weeks after the conization!

After the conization, the doctor examines the patient again. A PAP test in combination with an HPV test offers good security. A vaginal smear is only necessary if the CIN has not been completely removed and/or the HPV test is still positive.

Can you prevent CIN?

Cervical intraepithelial neoplasms are caused by HP viruses. All measures that detect an HPV infection at an early stage or, in the best case, prevent it, are suitable for prevention.

HPV vaccination

There are currently two vaccines against human papillomavirus on the market. They prevent HPV infection and protect against cell changes that can eventually lead to cervical cancer. Two vaccines are currently available:

  • Dual vaccine: protects against high-risk types HPV 16 and 18
  • Nine-fold vaccine: protects against high-risk types 16, 18, 31, 33, 45, 52 and 58 and low-risk types HPV 6 and 11 (additional protection against genital warts)

The HPV vaccination is a so-called dead vaccine. This means that the vaccine stimulates the immune system to produce antibodies, but cannot cause an infection itself.

The Standing Vaccination Commission (STIKO) recommends vaccination for all girls between the ages of nine and fourteen. Depending on the preparation, you will receive two or three doses. The vaccination works best if it is completed before the first sexual intercourse.

In principle, vaccination is also possible at a later point in time (after the first sex). Even if HPV infection has already occurred with a certain virus type, the vaccination still protects against the other virus types contained in the vaccine.

Vaccination is not suitable for treating an existing HPV infection. However, there is evidence that women who are vaccinated after a conization are less likely to develop CIN again.

As with all vaccinations, side effects are possible after an HPV vaccination. These include pain and swelling at the injection site, headache or dizziness. However, these reactions of the immune system are usually harmless and subside on their own within a few days.

screening examination

A CIN usually causes no symptoms. It is all the more important to attend the annual check-ups at the gynaecologist. Because: Regular checks (PAP test) prevent cell changes from developing undetected into cervical cancer.

Since January 2020, women over the age of 35 can have a human papillomavirus test every three years.

People who have been vaccinated with HPV shouldn’t do without gynecological check-ups either, because the current vaccines have so far only prevented some of the cancer-promoting HPV infections.

You may also like

Leave a Comment