There are different types of mammograms that are performed. The screening mammogram is a two-view exam of each breast consisting of craniocaudal (CC) and mediolateral oblique images (MLO). It is only used to screen asymptomatic patients. It is not used for patients that have a suspicious mass on physical examination. The diagnostic mammogram is done to further define the location of an abnormality detected during a screening mammogram or to clarify an indeterminate lesion. It is also performed in patients who have a suspicious lesion on physical exam or patients that have had breast cancer in the past and were treated with breast conservation techniques. Patients who have had breast augmentation also require diagnostic mammograms with specialized views of the breast. Exaggerated oblique projections, spot compressions, and magnified spot views are utilized in the diagnostic mammogram.
The radiologist looks for specific mammographic findings considered
suspicious for malignancy. Microcalcifications that are pleomorphic, 
5 in number, linear or clustered patterns are considered worrisome.
Masses that are spiculated, stellate, or associated with
microcalcifications are also considered suspicious. The radiologist also
looks for any new architectural distortion when compared to previous
mammograms. It is important that the patient has mammograms performed at
the same institution each time or brings mammograms that were previously
done for comparison purposes. Some indirect signs of malignancy include
asymmetry, dilated lactiferous ducts, skin or nipple thickening or
retraction.
There have been eight large randomized clinical trials performed to evaluate the utility of mammograms. Evidence suggests a powerful impact of mammography for women 50-69 years. No trial has yet recorded convincing evidence of a reduction in mortality rate for women aged 40-49 years. There have not been enough women over 70 years of age included in these trials to make definitive recommendations for that age group. Major health organizations have each reviewed the available data regarding mammography and made different conclusions. The most controversial age group is among patients who are 40-49 years old.
The current American Cancer Society Screening Recommendations are as follows:
- Mammograms every 1-2 years for women in their 40's
- Mammograms yearly for patients 50 years and older
One must remember that the mammogram is only one of the tools utilized for screening breast cancer patients. There is no mammographic abnormality in 15% of the patients diagnosed with cancer. Monthly breast self examination and regular physical examinations by your physician continue to be extremely important in the early diagnosis of breast cancer.