Mammographic changes following biopsy

After a core biopsy, there will be noticeable changes, both physically apparent, and in a subsequent mammogram. There may, for example, be skin thickening or retraction. There may be architectural distortion, hematoma, or seroma, especially if a lumpectomy was also performed. About 1/2 of women will have no mammographically detected breast changes following biopsy, but of those who do, the most commonly seen change at the initial mammographic followup is architectural distortion, (almost 48% of observed changes).

This page is still very useful, but a little bit somewhat “outdated”. So because of that, I came to the decision to create a newer version of this page with more up-to-date information on Mammography. Don’t get me wrong though, I would still use this page as well.

A thickening of the skin can account for about 17% of observed changes, and increased focal density (or a parenchymal scar) might account for about 15%.

About 1/2 of women undergoing an excisional biopsy will experience mammographic changes

Mammographic changes after excisional breast biopsy are often observed in up to 50% of patients. But, when post-biopsy mammographic changes are seen, they tend to remain stable during the next five years of follow-up. Therefore, once an expected post-biopsy change is first detected on mammography, it has to be monitored and any noted change can represent a developing malignancy. In the context of breast cancer screening programs, physicians have noted that statistically about 14% of suspicious abnormalities are in fact associated with previous breast biopsies.

Where breast cancer is confirmed, both follow-up ultrasound and mammography are useful in preparing for treatments

Following excisional biopsies for suspected breast cancer, both mammography and ultrasound are useful in determining the parameters for partial mastectomy or lumpectomy. Mammography tends to be slightly superior in detecting microcalcifications, whereas ultrasound is very good for differentiating tumors for hematomas.

So, often a combination of mammography and ultrasound will be used for women about to undergo breast-conserving surgery and radiation therapy for the treatment of confirmed breast cancer. However, this kind of ‘pre-treatment‘ follow-up imaging is something that occurs virtually right away once the cancer is discovered, and is not to be confused with benign mammographic changes on routine follow-up mammograms months after the initial biopsy.

Needle biopsies usually do not cause mammographically detectable changes

Mammographically detectable breast changes are much less common with needle biopsies. Immediately following a vacuum-assisted needle biopsy procedure, almost 80% of patients might develop a visible hematoma. Changes in breast density can be observed mammographically in about 45% of women undergoing a breast biopsy, in as little as one week following the procedure. But after six months, virtually no mammographic changes are observed. Changes in mammographic breast density are only seen in about 2% at most, for women having undergone a needle biopsy.

Follow-up mammography after DCIS detection and treatment is usually 6 months

Following the identification and treatment of DCIS, follow-up mammography is usually indicated at an interval of every six months, during the first five years. The main goal of follow-up mammography in a breast treated for breast cancer is the early recognition of local tumor recurrence. But, it is also important to know that there will be normal post-operative and post-radiation changes to the breast, which are expected and benign, but which can ‘overlap‘ signs of malignancy.

Some of these expected changes included the development of ‘masses‘ from fluid collection and scarring, also skin thickening, edema, and even calcifications. Skin thickening, edema, and postoperative fluid accumulations will be most noted during the first six months following treatments. Breast changes due to the effects of radiation therapy will usually resolve on their own after the first six months, and will be considered ‘stable‘ after about two years.

As a postoperative mass ‘resolves‘ and scarring occurs, a spiculated mass that can almost mimic a breast cancer tumor is quite often observed. But an experienced diagnostic radiologist will be quite aware of the differences between post-surgical changes and recurrent breast cancer, and will usually also ‘tailor‘ particular views and imaging techniques to increase visualization of these areas.

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For further reading, I suggest you visit this page that has information on Architectural distortion that is found on a breast mammogram, this page for some examples of mammogram image studies, and as well as this page about a discussion of conventional mammography.

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References

1. Brenner RJ, Pfaff JM. Mammographic changes after excisional breast biopsy for benign disease. AJR Am J Roentgenol.(Oct. 1996) 167(4):1047-52.
2. Taplin SH, Abraham L, Geller BM, Yankaskas BC, Buist DS, Smith-Bindman R, Lehman C, Weaver D, Carney PA, Barlow WE.Effect of previous benign breast biopsy on the interpretive performance of subsequent screening mammography.J Natl Cancer Inst. (July 2010) 102(14):1040-51.
3. Huber S, Wagner M, Medl M, Czembirek H. Benign breast lesions: minimally invasive vacuum-assisted biopsy with 11-gauge needles patient acceptance and effect on follow-up imaging findings. Radiology.(Mar. 2003) 226(3):783-90.
4. Lamm RL, Jackman RJ. Mammographic abnormalities caused by percutaneous stereotactic biopsy of histologically benign lesions evident on follow-up mammograms. AJR Am J Roentgenol. (Mar.2000) 174(3):753-6.
5. Burbank F.Mammographic findings after 14-gauge automated needle and 14-gauge directional, vacuum-assisted stereotactic breast biopsies. Radiology. (July 1997) 204(1):153-6.
6. Memis, A., Ustun, EE., Orguc, S. Mammographic and ultrasonographic evaluation of breast after excisional biopsy. European Journal of Ultrasound (Feb. 1997) Volume 5, Issue 1, Pages 47-51
7. Stidley, CA., Tollestrup, K., Frost, F., Bedrick, EJ., Petersen, HV. Mammography utilization after a benign breast biopsy among hispanic and non-Hispanic women.Cancer (May 2001) Volume 91, Issue 9, pages 1716–1723.
8. Morrow M, Strom EA, Bassett LW, Dershaw DD, Fowble B, Harris JR, O’Malley F, Schnitt SJ, Singletary SE, Winchester DP; American College of Surgeons; College of American Pathology; Society of Surgical Oncology; American College of Radiology. Standard for the management of ductal carcinoma in situ of the breast (DCIS). CA Cancer J Clin.(Oct. 2002) 52(5):256-76.

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