Two mass lesions in the left breast

Case contributed by Garth Kruger


Initial screening mammogram with no priors.

Patient Data

Age: 60 years
Gender: Female

Initial screening images of the left breast

The study is called Birads 0 and the patient recalled for workup. Do you agree?

The Birads classification is correct.  The workup will be additional views of the left breast and left breast ultrasound.

On the two views of the left breast there are 2 lesions visible, sen on both views. No previous for comparison.


Ultrasound of the larger, superior lesion in the left breast as indicated at 2 o'clock: This lesion is solid, mixed density and ultrasound guided needle biopsy shows an atypical fibroepithelial lesion and surgical excision followed. The second lesion was not found on ultrasound and the recommendation was that a follow up ultrasound be done in 6 months. The case was classified BI-RADS 3. Are you satisfied?

The case should have been called BI-RADS 0 and further workup should have been done to identify and sample (if appropriate) the lesion not seen on initial  ultrasound. This is inappropriate use of BI-RADS III. In fact there is no diagnosis at all of the second lesion. Management options at this stage would depend on resources at your disposal and where you work. MRI would be helpful and even second look ultrasound after MRI. If all else fails and you have no resources you should localize this lesion under mammographic guidance and have it removed. The teaching point is that extra imaging should have been done at this stage.


Six months after the case was called BI-RADS 3, the patient returns for mammogram and ultrasound of the left breast. Note the post surgical scarring related tot the surgical removal of the fibroepithelial lesion. As in most post surgical scars, it is virtually indistinguishable from the scirrous reaction of an infiltrating ductal carcinoma (IDC)

The second lesion deep inferiorly in the breast has now enlarged and has subtle lobulations of the surface.


Ultrasound of the enlarging lesion at 5 o'clock left breast is now quite alarming in appearance and typical of an infiltrating ductal carcinoma, which was confirmed on needle biopsy.

Case Discussion

The case shows that not seeing a lesion on one modality while it is visible on another, is not a diagnosis. This case shows the incorrect use of BI-RADS 3, which is always supposed to be most likely benign. Workup was incomplete after the first lesion was managed.

Low volume breast readers or those with low levels of experience should most likely use a second opinion from an experienced senologist before using BI-RADS 3.

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