Cervical Dysplasia
Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel, Jr., MD, FACP, FACR
What is cervical dysplasia?
Cervical dysplasia refers to the presence of precancerous changes of the
cells that make up the inner lining of the cervix, the opening to the womb (uterus). The term
dysplasia refers to the abnormal appearance of the cells when viewed under the
microscope. The degree and extent of abnormality seen on a tissue sample (such
as a Pap smear) was formerly referred to as mild, moderate,
or severe dysplasia. In recent years, this nomenclature has been replaced by two
newer systems. These systems are based upon changes in the appearance of cells
visualized when smears of individual cells (cytological changes) or tissue
biopsies (histological changes) are reviewed under a microscope.
- Squamous intraepithelial lesion is the
pathology terminology for
cervical dysplasia observed in smears of cells taken from the cervix.
Squamous refers to the type of cell that lines the cervix.
intraepithelial refers to the fact that
these cells are present in the lining tissue of the cervix.
- Cervical intraepithelial neoplasia is cervical dysplasia
that is observed on a cervical biopsy
or surgically removed cervix.
These classification systems will be
further discussed below.
What causes cervical dysplasia?
Cervical dysplasia is caused by infection of the cervix
with the human papillomavirus (HPV). Although there are over 100 HPV types, a subgroup of HPVs
have been found to infect the lining cells of the genital and reproductive tract
in women. HPV is a very common infection and is transmitted through sexual
contact; over 75% of sexually active women are thought to acquire the
virus at
one point or another. It is believed that over 6 million people become infected
with HPV every year in the US, and approximately 50% of those infected are
between the ages of 15 and 25. Most infections occur in young women, do not
produce symptoms, and resolve spontaneously without any long-term consequences.
The average length of new HPV infections in young women is 8-13 months. However,
it is possible to become re-infected with a different HPV type.
Some HPV infections persist over time rather than resolve,
and the reason why the infection persists in these women is not fully
understood. Factors that may influence persistence of the infection include:
- advancing age,
- duration of the infection, and
- being infected with a "high-risk"
HPV type (see below).
Persistent HPV infection has been shown to play a causal
role in the development of genital warts and precancerous changes (dysplasia) of
the uterine cervix as well as cervical cancer. Even though HPV infection appears
to be necessary for the development of cervical dysplasia and cancer, since not
all women who have HPV infection develop dysplasia or cancer of the cervix. Additional, yet uncharacterized factors must also be important in causing cervical dysplasia and
cancer. Since HPV infections are transmitted primarily by sexual intimacy, the
risk of infection increases as the number of sexual partners increases.
Among the HPVs that infect the genital tract, certain types typically cause
warts or mild dysplasia ("low-risk" types; HPV-6, HPV-11), while other types
(known as "high-risk" HPV types) are more strongly associated with severe
dysplasia and cervical cancer (HPV-16, HPV-18). Cigarette smoking and
suppression of the immune system (such as with concurrent HIV infection) have
been shown to increase the risk for HPV-induced dysplasia and cancer of the
cervix.
The HPV types that cause cervical cancer also have been
linked with both anal and penile
cancer in men as well as a subgroup of head and neck cancers in both
women and men.
Next: Are there symptoms of cervical dysplasia? »
- Gardasil (HPV Vaccine) - Gardasil HPV vaccine (recombinant human papillomavirus quadrivalent vaccine) drug class, prescription, injection, preparation, storage, dosage, drug interaction, pregnancy and nursing, and side effects information.
- Pap Smear - Read about Pap smear, a test to screen for cervical cancer, and precancerous changes in the cervix. Risk factors for abnormal Pap include HPV, smoking medicaitons, and a weakened immune system.
- Sexually Transmitted Diseases in Women (STDs) - Learn and become aware of common STDs in women, including descriptions, symptoms, diagnosis, and treatments of each type of infection.
Latest Medical News
Womens Health RSS