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
- 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
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:
- Forty-five thousand women die of breast cancer in the United States each 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 over 90 percent 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.
- benign breast disease
- 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:
- not having children
- not breastfeeding
- oral contraceptives
- obesity and a high-fat diet
- physical inactivity
- 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.
National Cancer Institute Guideline for
Women in their 40s and older should have a screening mammogram on a regular basis, every one to two years.
American Cancer Society Guideline for
Women 40 years of age and older should have a screening mammogram every year.