What is a mammogram?
A mammogram is an x-ray examination of the breast. It is used to detect
and diagnose breast disease in women who either have breast problems such
as a lump, pain, or nipple discharge, as well as for women who have no breast
complaints.
What are the different types of mammograms?
A screening mammogram is an x-ray of the breast used to detect
breast changes in women who have no signs of breast cancer. It usually
involves two x-rays of each breast. Using a mammogram, it is possible
to detect a tumor that cannot be felt.
A diagnostic mammogram is an x-ray of the breast used to diagnose
unusual breast changes, such as a lump, pain, nipple thickening or discharge,
or a change in breast size or shape.
A diagnostic mammogram is also used to evaluate abnormalities detected
on a screening mammogram. It is a basic medical tool and is appropriate
in the work-up of breast changes, regardless of a woman's age.
Mammography has been used for about 30 years, and in the past 15 years
technical advancements have greatly improved both the technique and results.
Today, specialized equipment, used only for breast x-rays, produce studies
that are high in quality but low in radiation dose. Radiation risks are
considered to be negligible.
How is a mammogram performed?
Usually, a mammogram is done on an outpatient basis, although it can
be part of inpatient care. There is no specific preparation for the examination.
However, a woman should not wear deodorant, powders, or lotions under
the arms on the day of the examination, as these substances can interfere
with the images.
Although each hospital may have specific protocols in place, generally,
a mammogram procedure follows this process:
- The patient should describe any symptoms or problems to the technologist
prior to the examination (if any).
- The patient undresses from the waist up and is given a gown to wear.
- The patient is positioned at the mammography unit, seated, standing,
or lying down.
- The breast is positioned between two plates of the mammography unit,
and pressure applied to compress the tissue. (This may produce temporary
discomfort.) Breast compression is necessary in order to obtain the
best image with the least amount of radiation possible.
- The patient is asked to hold her breath for a few seconds while the
x-rays are taken.
- The technician steps behind a protective window and the image is taken.
- Each breast may be x-rayed at least two times from above and from
the side positions to produce the films for the physician to review.
- After the x-rays are made, the patient is asked to wait for a short
time until the radiologist can review the films to determine if additional
x-rays are necessary.
What conditions does a mammogram show?
A mammogram helps to identify the following conditions:
- calcifications - tiny mineral deposits within the breast tissue.
There are two categories of calcifications:
- macrocalcifications - coarse calcium deposits that usually
indicate degenerative changes in the breasts, such as the following:
- aging of the breast arteries
- old injuries
- inflammations
- microcalcifications - tiny (less than 1/50 of an inch)
specks of calcium. When many microcalcifications are seen in one
area, they are referred to as a cluster.
- masses - may occur with or without associated calcifications,
and may be due to different causes, including the following:
- cyst - a non-cancerous collection of fluid in the breast.
Cysts cannot be diagnosed by physical examination alone nor by mammography
alone. Either breast ultrasound or aspiration with a needle is required.
If a mass is not a cyst, then further imaging may be necessary.
- benign breast conditions - masses can be monitored with
periodic mammography, but others may require immediate or delayed
biopsy.
- breast cancer
Mammography guidelines:
In the United States, breast cancer is the most common form of cancer
among women. Almost 185,000 new cases of breast cancer are diagnosed each
year. Only lung cancer causes more cancer deaths among women than breast
cancer.
Consider the following additional breast cancer facts:
- American Cancer Society (ACS) estimates for 2003 include 211,300 new
cases of invasive breast cancer in women being diagnosed in the US.
In addition, ductal carcinoma in situ will be responsible for 55,700
new cases this year.
- One in eight women in the United States may develop breast cancer.
- Breast cancer risk increases with age. The greatest incidence of breast
cancer occurs in women over the age of 50.
- Mammography can detect an overwhelming majority of breast cancers
before they become large enough to feel or cause symptoms.
What are the risk factors for breast cancer?
Any woman may develop breast cancer. However, the following risk factors
may increase the likelihood of developing the disease.
1. Risk factors that cannot be changed:
- gender
Breast cancer occurs nearly 100 times more often in women than in
men.
- aging
A majority of cases of breast cancer occur after age 50.
- personal history of breast cancer
- previous breast irradiation
- family history and genetic factors
Having a close relative, such as a mother or sister, with breast cancer
increases the risk.
- previous breast biopsy in which the tissue showed atypical hyperplasia
- menstrual periods that began early in life
- menopause began later in life
2. The most frequently cited lifestyle-related risk factors:
- smoking
- not having children
- not breastfeeding
- oral contraceptives
- obesity and a high-fat diet
- physical inactivity
- alcohol
- estrogen replacement therapy
- induced abortion
3. Environmental risk factors:
Exposure to pesticides, or other chemicals, is currently being examined
as a possible risk factor for breast cancer.
It has been found that 70 percent of the women diagnosed with breast cancer
had no significant risk factors. This means that monthly self-examination
of the breasts, regular screening mammograms, and clinical breast examinations
are extremely important in the early detection of breast cancer.
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National Cancer Institute Guideline for Screening Mammography:
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American Cancer Society Guideline for Screening Mammography:
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| Women in their 40s and older should
have a screening mammogram on a regular basis, every one to two years. |
Women 40 years of age and older
should have a screening mammogram every year. |
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