What Are the Causes of Incomplete Mammogram Results?

Don't panic if you've been told your mammogram results are incomplete. This usually means the radiologist needs more information to make the most accurate assessment of your results. The radiologist may request further studies or copies of previous studies for comparison purposes. After examining all information available, your mammogram will be categorized according to BI-RADS, or the Breast Imaging Reporting and Database System used by the American College of Radiology.


Mammograms are low dose X-rays of breast tissue used to detect breast cancer 1. The National Cancer Institute recommends mammograms be obtained every one to two years for women age 40 and over 1. You may be asked to obtain a baseline mammogram sooner than age 40 so that it may be compared with later mammograms. Women with a history of breast cancer or a family history of breast cancer may need mammograms sooner than age 40 and more often than every one to two years 1.

Types of Mammograms

A screening mammogram is done for women with no signs or symptoms of breast cancer. These x-rays can detect breast lesions which cannot yet be seen or felt by physical exam. Diagnostic mammograms are done when signs or symptoms of breast pathology are present, including lumps, nipple discharge, pain or tenderness, thickened skin over the breast, or a change in the breasts size or shape. A diagnostic mammogram may also be done as a follow-up if any abnormalities were found on your screening mammogram, or if the radiologist needs more information.

Digital Mammography

Digital mammograms are different from conventional mammograms in that the x-rays taken are stored directly onto a computer and not on film. According to the National Cancer Institute, because:

  • digital images can be manipulated
  • magnified
  • or enhanced
  • subtle differences between normal
  • abnormal breast tissue may be more easily detected than with conventional film mammography 1

Digital mammography may be appropriate for pre- or perimenopausal women with dense breasts. However, both types of mammography are equally able to detect breast cancer.


BI-RADS provides standardized assessment of breast imaging, whether the imaging is a mammogram, an ultrasound, or a magnetic resonance imaging scan. If your assessment is complete, your imaging will be assigned to one of six categories: \" 1) negative, 2) benign finding, 3) probably benign finding--an initial short-interval follow-up suggested, 4) suspicious abnormality--a biopsy should be considered, 5) highly suggestive of malignancy--appropriate action should be taken, or 6) known biopsy-proven malignancy--appropriate action should be taken.\"

Incomplete Result

If your doctor determines that more information is needed before determining what category to assign your imaging, it will be assigned to BI-RADS category 0 (zero): \"Assessment is incomplete--need additional imaging evaluation and/or prior mammograms for comparison.\" According to the National Women's Health Information Center, if you have dense or fibrous breasts, you may need further evaluation with breast ultrasound or MRI 1. If you've had other breast imaging in the past, your radiologist may want to view the images and reports to compare them to the current X-ray, in order to make the most accurate assessment possible.