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Can someone please help me understand BIRAD D4?


Megan M's picture
Megan M
Posts: 3001
Joined: Dec 2009

From what I could find, Bi-Rads stands for Breast Imaging Reporting and Data Systems. Breasts are staged by density and D4=extremely dense.

Was this on one of your test reports or did your oncologist tell you this? 


Posts: 2
Joined: May 2013

Hi Megan

Thank you. It was my mammogram test . I need to schedule a biopsy.



jessiesmom1's picture
Posts: 827
Joined: Jun 2010

The BIRADS classification system indicates a radiologist's opinion on the presence or absence of breast cancer. It has nothing to do with breast density. BIRADS 4 = a diagnosis of suious malignancy. It is not characteristic of breast cancer but has a "reasonable probability" of being malignant (3-94%). A biopsy should be considered with this diagnosis.

I am glad  you are following through. Good luck and keep us posted.


Ritzy's picture
Posts: 4384
Joined: Aug 2009

The 4 after the BiRads does mean extremely dense, like Megan wrote.

Sue :)

Posts: 1186
Joined: Dec 2010

I found a website that talks about a BIRADS D4 diagnoses as the D4 indicating dense breasts (http://www.womenshealthsection.com/content/gyno/gyno018.php3)

Currently, the most common clinical measure of density is the Breast Imaging Reporting and Data Systems (BI-RADS) density method, proposed by the American College of Radiology (3)(17). BI-RADS density is a subjective measure used by radiologists to classify a mammogram as follows:

  • D1: Fatty;
  • D2: Scattered density;
  • D3: Heterogeneously dense; or
  • D4: Extremely dense.

Computer assisted methods are used to estimate quantitative measures of MBD, including percent density (percentage of the overall breast showing dense tissue; PD), absolute dense area, and non-dense area (3)(16).

jessiesmom1's picture
Posts: 827
Joined: Jun 2010

According to the American College of Radiology - BI-RADS-Mammography, 4th Edition:

Category 4
Suious Abnormality—Biopsy Should Be Considered:
(See Guidance Chapter*):

This category is reserved for findings that do not have the
classic appearance of malignancy but have a wide range
of probability of malignancy that is greater than those in
Category 3. Thus, most recommendations of breast
interventional procedures will be placed within this
category. By subdividing Category 4 into 4A, 4B and 4C as
suggested in the guidance chapter, it is encouraged that
relevant probabilities for malignancy be indicated within
this category so the patient and her physician can make
an informed decision on the ultimate course of action.


Category 4:

Category 4 is used for the vast majority of findings
prompting breast interventional procedures
ranging from aspiration of complicated cysts to
biopsy of pleomorphic calcifications. Many institutions
have, on an individual basis, subdivided
Category 4 to account for the vast range of lesions
subjected to interventional procedures and corresponding
broad range of risk of malignancy. This
allows a more meaningful practice audit, is useful
in research involving receiver-operating characteristic
(ROC) curve analysis, and is an aid for
clinicians and pathologists. The optional division

of Category 4 into three subdivisions internally
at the facility level helps to accomplish these goals.

Category 4A
Category 4A may be used for a finding needing
intervention but with a low suion for
malignancy. A malignant pathology report not
expected and a 6-month or routine follow-up
after a benign biopsy or cytology is appropriate.
Examples of findings placed in this
category may be a palpable, partially cirscribed
solid mass with ultrasound features
suggestive of a fibroadenoma, a palpable
complicated cyst or probable abscess.

Category 4B
Category 4B includes lesions with an intermediate
suion of malignancy. Findings in
this category warrant close radiologic and
pathologic correlation. Follow-up with a
benign result, in this situation, depends on
concordance. A partially cirscribed, partially
indistinctly marginated mass yielding
fibroadenoma or fat necrosis is acceptable,
but a result of papilloma might warrant
excisional biopsy.

Category 4C
Category 4C includes findings of moderate
concern, but not classic (as in Category 5)
for malignancy. Examples of findings placed
in this category are an ill-defined, irregular
solid mass or a new cluster of fine pleomorphic
calcifications. A malignant result in this
category is expected.
These internal divisions of Category 4 should
encourage pathologists to initiate further
evaluation of benign results in a Category 4C,
and should allow clinicians to better understand
follow-up recommendations after biopsy for findings placed in each subset of
Category 4.

Posts: 1186
Joined: Dec 2010

Jessiemom1. It would appear that BIRADS looks for at least two things: abnormalities in the breast AND breast density. I am thinking that a D paired with a 4 means that the Density of the breast is at a level 4 meaning that the breast is extremely dense. I am assuming that there was also something suious found that indicates a need for a biopsy.


Mammograms and Other Breast Imaging Procedures

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Doent Topics
What is a mammogram?
Types of mammograms
How is a mammogram done?
Help with mammogram costs
Regulation of mammography
What does the doctor look for on a mammogram?
Breast biopsy
Mammogram reports – BI-RADS
Mammograms in special cirstances
Improving mammograms
Other breast imaging tests
Experimental and other breast imaging methods
To learn more

Previous Topic

Breast biopsy

Mammogram reports – BI-RADS

The American College of Radiology (ACR) has developed a standard way of describing mammogram findings. In this system, the results are sorted into categories numbered 0 through 6. This system is called the Breast Imaging Reporting and Data System (BI-RADS). Having a standard way of reporting mammogram results lets doctors use the same words and terms and ensures better follow up of suious findings. Here’s a brief review of what the categories mean:

X-ray assessment is incomplete

Category 0: Additional imaging evaluation and/or comparison to prior mammograms is needed.

This means a possible abnormality may not be clearly seen or defined and more tests are needed, such as the use of spot compression (applying compression to a smaller area when doing the mammogram), magnified views, special mammogram views, or ultrasound.

This also suggests that the mammogram should be compared with older ones to see if there have been changes in the area over time.

X-ray assessment is complete

Category 1: Negative

There’s no significant abnormality to report. The breasts look the same (they are symmetrical) with no masses (lumps), distorted structures, or suious calcifications. In this case, negative means nothing bad was found.

Category 2: Benign (non-cancerous) finding

This is also a negative mammogram result (there’s no sign of cancer), but the reporting doctor chooses to describe a finding known to be benign, such as benign calcifications, lymph nodes in the breast, or calcified fibroadenomas. This ensures that others who look at the mammogram will not misinterpret the benign finding as suious. This finding is recorded in the mammogram report to help when comparing to future mammograms.

Category 3: Probably benign finding – Follow-up in a short time frame is suggested

The findings in this category have a very good chance (greater than 98%) of being benign (not cancer). The findings are not expected to change over time. But since it’s not proven benign, it’s helpful to see if an area of concern does change over time.

Follow-up with repeat imaging is usually done in 6 months and regularly thereafter until the finding is known to be stable (usually at least 2 years). This approach helps avoid unnecessary biopsies, but if the area does change over time, it allows for early diagnosis.

Category 4: Suious abnormality – Biopsy should be considered

Findings do not definitely look like cancer but could be cancer. The radiologist is concerned enough to recommend a biopsy. The findings in this category can have a wide range of suion levels. For this reason, some doctors may divide this category further:

  • finding with a low suion of being cancer
  • finding with an intermediate suion of being cancer
  • finding of moderate concern of being cancer, but not as high as Category 5

Not all doctors use these subcategories.

Category 5: Highly suggestive of malignancy – Appropriate action should be taken

The findings look like cancer and have a high chance (at least 95%) of being cancer. Biopsy is very strongly recommended.

Category 6: Known biopsy-proven malignancy – Appropriate action should be taken

This category is only used for findings on a mammogram that have already been shown to be cancer by a previous biopsy. Mammograms may be used in this way to see how well the cancer is responding to treatment.

BI-RADS reporting for breast density

Mammogram reports can also include an assessment of breast density. BI-RADS classifies breast density into 4 groups:

BI-RADS 1: The breast is almost entirely fat

This means that fibrous and glandular tissue makes up less than 25% of the breast

BI-RADS 2: There are scattered fibroglandular densities

Fibrous and glandular tissue makes up from 25 to 50% of the breast.

BI-RADS 3: The breast tissue is heterogeneously dense

The breast has more areas of fibrous and glandular tissue (from 51 to 75%) that are found throughout the breast. This can make it hard to see small masses (cysts or tumors).

BI-RADS 4: The breast tissue is extremely dense

The breast is made up of more than 75% fibrous and glandular tissue. This can lead to missing some cancers.

In some states, the summary of the mammogram report that is sent to patients (sometimes called the lay summary) must contain information about breast density. This information may be worded in lay language instead of the BIRADS categories. Women whose mammograms show BI-RADS 3 or 4 for breast density may be told that they have “dense breasts.”

Megan M's picture
Megan M
Posts: 3001
Joined: Dec 2009

Sally, did you schedule your biopsy yet?  Let us know when you do.

Good luck, Megan

jenny57's picture
Posts: 6
Joined: Jul 2014

I don't know what BIRAD 4 is!


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