Answer
Mammographic appearances of postsurgical changes after breast reduction, breast reconstruction, and breast augmentation commonly are encountered. A variety of surgical techniques are used in breast reduction surgery. One of the most common is the keyhole incision technique. In this procedure, an incision is made around the areola and extended vertically in the 6-o'clock position to the inferior mammary fold. Typical mammographic findings may include alteration of the parenchymal architecture, cranial displacement of the nipple, patchy densities due to tissue removal and scarring, and the development of fat necrosis. Approximately 6 months after surgery, a new baseline mammogram should be obtained. Any new findings from the baseline examination, such as a developing density, mass, or calcifications, require a thorough evaluation, including possible tissue sampling.
Breast reconstruction may be performed after a mastectomy by means of reconstruction with autogenous tissue transfer and/or implants. The most common autogenous tissue transfer site is from the panniculus or from a free myocutaneous flap. The most frequent location of the donor tissue is from a flap harvested from the latissimus dorsi muscle or the transverse rectus abdominis muscle (TRAM) flap.
Mammographic imaging of the reconstructed breast may be requested for the evaluation of a clinically suspicious finding, such as a palpable mass. Standard mammographic views are performed with additional views (compression, magnification, tangential) and ultrasonography if needed. In general, most of the mammographic and clinical findings are related to the development of dystrophic changes within the donor tissue, such as oil cysts and fat necrosis. Typically, dystrophic changes can be recognized easily on the mammogram as benign. However, fat necrosis, dystrophic microcalcifications, and scarring also can mimic cancer, thus prompting biopsy.
(See the images below.)
Mediolateral oblique mammogram of the breast shows a subpectoral (behind the muscle) silicone implant. Free silicone is noted outside the implant, within the soft tissue of the upper breast, consistent with implant rupture (see arrows).
Mediolateral oblique image of a transverse rectus abdominis muscle (TRAM) flap used to augment the breast volume instead of an implant. The native breast tissue is noted anterior to the TRAM flap and produces this unusual architecture.
The postsurgical mammographic observations identified after breast augmentation are related to the technical placement of the implant and the type of the implant. Standard and implant-displaced views are recommended. Assessment of the implants includes the location (subglandular or subpectoral), type (silicone, saline, mixed), contour (evaluation for possible rupture or weakening), and evaluation for possible complications (rupture, capsular formation). The evaluation of the native breast tissue may be obscured by the implant, thus hampering breast cancer detection. Rarely, breast tissue may be augmented by using native tissue harvested from the muscle or pedunculus. This produces an unusual mammographic appearance.
In a retrospective review of 64 patients who underwent partial mastectomy with immediate oncoplastic reduction mammoplasty reconstruction, although substantial tissue rearrangement was performed, there were low rates of abnormal postoperative mammograms and subsequent biopsies during the first 2 years following the procedure. [5]
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Prebiopsy craniocaudal mammogram demonstrates a 1-cm mass in the medial aspect of the breast (see arrow). Subsequent stereotactic biopsy was performed.
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Postbiopsy craniocaudal mammogram of the breast obtained immediately after stereotactic biopsy of a lesion (same patient as in Image above). Interval development of a mass has occurred in the biopsy bed (see arrow); this finding is consistent with a hematoma. A marking clip has been placed.
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Mediolateral magnification view of the tumor bed after breast conservation treatment. A few coarse calcifications are noted consistent with fat necrosis. Mild architectural distortion is apparent in the lumpectomy site (see arrow). A scar marker was placed over the incision site.
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Craniocaudal view in a patient after a reduction mammoplasty. Scattered parenchymal densities, architectural distortion, and extensive calcifications (due to fat necrosis) are noted (see arrows).
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Craniocaudal mammogram demonstrating multiple oil cysts. Note the multiple radiolucent masses with smooth internal margins and typical eggshell-like calcifications (see arrows). Frequently, a history of previous trauma or surgery can be elicited from the patient.
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Mediolateral oblique mammogram in a patient 3 years after a mastectomy and reconstruction with a transverse rectus abdominis muscle (TRAM) flap. The patient noticed the development of palpable firm masses in the upper-outer portion of the reconstructed breast (see arrows). The mammogram demonstrates the typical appearance of a TRAM flap. In addition, extensive macrocalcifications have developed related to fat necrosis. These calcifications corresponded to the palpable mass.
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Immediate mediolateral view after a stereotactic biopsy for calcifications in the inferior breast. Little mammographic evidence reveals that a biopsy has occurred, except for the placement of a clip (see arrow).
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Craniocaudal mammogram after breast conservation treatment, axillary dissection, and radiation therapy. Note the skin and trabecular thickening (see arrows).
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Craniocaudal mammogram demonstrating extensive keloid scarring in the medial aspect of the breast. Note the irregular, macrolobulated, circumscribed densities with wide margins, outlined by a thin surrounding halo of air (see arrows). The keloids are superimposed on the breast tissue on the mammogram and can mimic breast lesions. Careful documentation of skin lesions is important so that dermal lesions are not confused with breast pathology.
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Mediolateral oblique view obtained after breast conservation treatment and axillary dissection in a patient with a 2-cm invasive ductal cancer. Mild architectural distortion is noted in the tumor bed in the upper quadrant of the breast (see arrow). Clips are placed within the tumor bed to assist with radiation therapy planning.
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Craniocaudal mammogram obtained 2 years after lumpectomy, axillary dissection, and chemotherapy. Note the periareolar skin thickening and retraction and scarring extending from the nipple to the chest wall as a result of the surgery (see triangles). Coarse macrolobulated calcifications have developed in the surgical site (see arrow).
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Craniocaudal mammogram obtained in the patient in Image 11 who presented with a palpable mass directly behind the nipple within the prior tumor site, 6 years later. An interval increase has occurred in the amount of dystrophic calcifications and scarring (see triangles) in the tumor bed. The palpable mass corresponded to the large calcification (see arrow). Fine-needle aspiration demonstrated fat necrosis.
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Mediolateral oblique mammogram of the breast shows a subpectoral (behind the muscle) silicone implant. Free silicone is noted outside the implant, within the soft tissue of the upper breast, consistent with implant rupture (see arrows).
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Mediolateral oblique image of a transverse rectus abdominis muscle (TRAM) flap used to augment the breast volume instead of an implant. The native breast tissue is noted anterior to the TRAM flap and produces this unusual architecture.
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Ultrasonogram demonstrates 2 ovoid, smooth, thin-walled, anechoic masses with acoustic enhancement. The larger is anechoic, compatible with a simple cyst (see arrow). The smaller contains some internal echoes, although it also was shown to represent a cyst.
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Ultrasonogram demonstrates a complex mass with internal echoes (see arrow). This appearance is consistent with a resolving hematoma after surgery. Solid masses (benign and malignant) can also demonstrate this sonographic appearance.
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Ultrasonogram demonstrates acoustic shadowing and an irregular hypoechoic mass (see arrow). This appearance can be seen in cancers as well as in postsurgical scars.
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Lateral scintimammogram obtained with technetium-99m sestamibi shows a 2-cm palpable breast cancer in the center of the breast (see arrow).
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Recent hematomas and/or seromas are frequently seen as a round or oval mass in the biopsy or lumpectomy site. Air-fluid levels may be observed in the acute postoperative period. Over time, the mass (hematoma) resolves.
