Breast Imaging: A Core Review (15 page)

15
 
Answer D.
Neurofibromatosis, breast cysts, melanoma, and fibroadenomas are all in the differential for multiple bilateral breast masses. It is the diffuse shadowing or “snowstorm” appearance on ultrasound that is classic for free silicone. Free silicone injection into the breasts is not approved in the United States, but is still practiced in other parts of the world, such as Asia and South America. Free silicone injection can present as large high density masses, some with curvilinear calcification. Masses demonstrate foci of low signal intensity on fat-suppressed T1-weighted images and high signal intensity on water-suppressed T2-weighted images, and MRI may be essential in evaluating for malignancy.

References: Caskey CI, Berg WA, Hamper UM, et al. Imaging spectrum of extracapsular silicone: correlation with US, MR imaging, mammographic, and histopathologic findings.
Radiographics
1999;19:S39–S51.
Cheung YC, Su MY, Ng SH, et al. Lumpy silicone-injected breasts: enhanced MRI and microscopic correlation.
Clin Imaging
2002;26:397–404.
Leibman AJ, Misra M. Spectrum of imaging findings in the silicone-injected breast.
Plast Reconstr Surg
2011;128:28e–29e.

16a
 
Answer C.
The test is indicated in this patient. Due to increased parenchymal enhancement during the secretory phase, there is increased risk of false-positive MRI results. Optimal timing of an MRI study of the breasts is during the 2nd week of the menstrual cycle.

Reference: Morris EA, Bassett LW, Berg WA, et al.
ACR Practice Guideline for the Performance of Contrast-Enhanced Magnetic Resonance Imaging (MRI) of the Breast
. Reston, VA: American College of Radiology (ACR); 2008:7.
www.acr.org/secondarymainmenucategories/quality_safety/guidelines/breast/mri_breast.aspx

16b
 
Answer D.
The patients history of treated non-Hodgkin lymphoma places the patient at a >20% lifetime risk of breast cancer, due to exposure to mantle radiation. Although breast augmentation can also be an indication, it is typically performed without contrast.

Reference: Morris EA, Bassett LW, Berg WA, et al.
ACR Practice Guideline for the Performance of Contrast-Enhanced Magnetic Resonance Imaging (MRI) of the Breast
. Reston, VA: American College of Radiology (ACR); 2008:7.
www.acr.org/secondarymainmenucategories/quality_safety/guidelines/breast/mri_breast.aspx

17
 
Answer D.
Yearly mammograms are recommended starting at age 40 and continue as long as the woman is in good health.

Reference:
http://www.cancer.org/Healthy/FindCancerEarly/CancerScreeningGuidelines/american-cancer-society-guidelines-for-the-early-detection-of-cancer

18
 
Answer D.
Breast cancers in the subareolar region are subject to the rich lymphatics of the Sappey plexus; therefore, they are at risk of earlier metastatic spread compared to other breast cancers. Breast cancers in this location are more common in the male population than in females. In females, breast cancer in the subareolar region constitutes ~1% of all breast cancers. Breast cancers in this location are often difficult to detect due to breast tissue summation artifact, particularly due to retroareolar fibrosis.

Reference: Tabar L, Tot T, Dean P.
Breast Cancer the Art of and Science of Early Detection with Mammography.
New York, NY: Thieme; 2005:259, 346.

19
 
Answer B.
The mass is located in the upper inner quadrant, which is the second most common location for breast cancers after the upper outer quadrant. Approximately 17% of all breast cancer in women occurs in the upper inner quadrant. The retroglandular clear space, the space between the posterior border of the glandular tissue and the anterior border of the pectoralis major muscle, and the medial breast are important locations to evaluate for an abnormality on the CC view, which is the location of the finding on the CC view in this case.

Reference: Tabar L, Tot T, Dean P.
Breast Cancer the Art of and Science of Early Detection with Mammography.
New York, NY: Thieme; 2005:259.

20
 
Answer C.
Sixty-one percent of all breast cancers in females occur in the upper outer quadrant, making this the most common location for breast cancer. It is important to evaluate the retroglandular clear space on the MLO view for a potential finding. The retroglandular clear space is the predominately fatty tissue between the posterior border of the glandular tissue and the anterior border of the pectoralis major muscle on the MLO view, which is the location of the mass in this case.

Reference: Tabar L, Tot T, Dean P.
Breast Cancer the Art of and Science of Early Detection with Mammography.
New York, NY: Thieme; 2005:259.

21
 
Answer C.
On ultrasound, hamartomas present as an encapsulated heterogeneous masses with both fibroglandular tissue and fat. This is easily distinguished from the other fat-containing masses provided as possible answers. The most appropriate BI-RADS classification for this lesion is BI-RADS 2, benign. This is considered a “don’t touch” lesion, and further intervention is unnecessary unless the patient is bothered by the mass and desires surgical resection.

Reference: Appleton CM, Wiele KN.
Breast Imaging Cases (Cases in Radiology).
New York, NY: Oxford University Press; 2012:21–22.

22
 
Answer B.
These are classic secretory calcifications and are benign. No additional evaluation is needed. They develop from the calcification of debris within dilated ducts. Secretory calcifications typically present as coarse rod-like branching calcifications in a ductal distribution. It is important to understand that these are not the calcifications of DCIS, which are more likely to present as fine, pleomorphic calcifications.

Reference: Evans AJ.
Breast Calcifications: A Diagnostic Manual.
San Francisco, CA: Cambridge University Press; 2002:16–18.

23a
 
Answer B.

23b
 
Answer B.
These are bilateral secretory calcifications. They have a classic thick rod-shaped appearance and often, but not always bilateral. They can be seen converging toward the nipple. They are always benign and do not need any further evaluation.

Reference: Shah BA, Fundaro GM, Mandava S.
Breast Imaging Review: A Quick Guide to Essential Diagnoses
. 1st ed. New York, NY: Springer; 2010:6–7.

24a
 
Answer D.

24b
 
Answer C.
The tattoo sign is a finding seen on mammograms. It appears as calcifications that maintain a fixed and reproducible relationship to one another on mammograms obtained with similar projections at different times. In addition to the tattoo sign, there is another similar unnamed mammographic sign that also indicates the presence of dermal calcifications, and it should be applied in all cases of peripheral calcifications. The tattoo sign is made up of calcifications that maintain a fixed and reproducible relationship to one another on mammograms obtained with similar projections at different times. The unnamed sign is made up of microcalcifications that maintain a fixed relationship to one another on mammograms obtained with different projections during the same examination.

Reference: Loffman Felman RL. Signs in imaging.
Radiology
2002;223:481–482.

25
 
Answer B.
Multiple partially circumscribed masses are a relatively common occurrence, with studies estimating a rate close to 2% for every 100 screening mammograms. The vast majority of these masses represent cysts or fibroadenomas. There is no increased risk of cancer in women with multiple partially circumscribed breast masses if management was limited to annual mammography follow-up.

Reference: Leung JW, Sickles EA. Multiple bilateral masses detected on screening mammography: assessment of need for recall imaging.
Am J Roentgenol
2000;175(1):23–29.

26
 
Answer A.
Lesions laterally in the breast project higher on the mediolateral oblique (MLO) view than they are actually located in the breast and lesions in the medial breast project lower on the MLO view than they are actually located. Lateral lesions shift lower in position on the ML view. Lesions in the medial breast shift higher on the ML view. “Lead (lateral) sinks, muffins (medial) rise.” Of note, lesions located more centrally in the breast shift little or not at all between the MLO and ML views.

Reference: Harvey JA, Nicholson BT, Cohen MA. Findings early invasive breast cancers: A practical approach.
Radiology
2008;248:61–76.

27
 
Answer A.
HER2 positive breast cancers usually demonstrate rapid growth and spread. Approximately 20% of newly diagnosed breast cancer is HER2 positive. HER2 breast cancers are more aggressive than HER2 negative cancer and are less responsive to hormonal treatment. Triple negative breast cancers do not have a good prognosis.

Reference: Lakhani SR, Van De Vijver MJ, Jacquemier J, et al. The pathology of familial breast cancer: Predictive value of immunohistochemical markers estrogen receptor, progesterone receptor, HER-2, and p53 in patients with mutations in BRCA1 and BRCA2.
J Clin Oncol
2002;20:2310–2318.

28a
 
Answer B.
This breast MRI demonstrates left duct ectasia, which is a benign finding, BI-RADS category 2. Duct ectasia is a common, benign finding seen on breast MRI. It may be seen unilateral or bilateral, focal or diffuse. Duct ectasia is ductal dilatation with internal proteinaceous content or debris; it is characterized by high T1 signal in a ductal distribution on the precontrast T1 sequence. Because the proteinaceous content has inherent high T1 signal, it will also be high signal on the postcontrast T1. However, since the finding is due to precontrast signal and not truly enhancing, high signal will not be seen in the area on the subtraction sequence. It is important to examine the subtraction sequence closely to ensure that no actual enhancement is present. Answer choice A is incorrect because the finding is not incomplete (BI-RADS category 0); no additional imaging is necessary. Answer choices C, D, and E are not correct; short-term follow-up or biopsy is not indicated.

28b
 
Answer E.
The correct follow-up recommendation for this patient based on the included images is an annual screening breast MRI in addition to her annual left mammogram. Answer choice A is incorrect as additional ultrasound evaluation is not needed to further characterize the finding. Surgical referral is not necessary for this finding. As long as the patient is stable and asymptomatic, she can continue with her standard clinical follow-up. Therefore, answer choice B is incorrect. Answer choice C is not correct because MRI biopsy is not necessary. Duct ectasia alone is not a suspicious finding on MRI. Again, it is important to examine the area closely for enhancement on the subtraction sequence. DCIS may also present with high T1 signal on the precontrast sequence with possible blood/debris in the duct. However, it would be seen as high T1 signal on both pre- and postcontrast T1 as well as concomitant high signal/enhancement on the subtraction sequence. Answer choice D is incorrect; this is a benign finding. Annual, rather than 6-month follow-up breast MRI is indicated.

Reference: Morris EA, Liberman L, eds.
Breast MRI Diagnosis and Intervention
. New York, NY: Springer; 2005:25–26, 437–440.

29
 
Answer B.
This patient has inflammatory carcinoma. The findings of a dominant mass in the upper outer quadrant of the breast in the presence of skin and trabecular thickening confirm the diagnosis. This patient requires a core biopsy of the mass to confirm the diagnosis. In the absence of a dominant mass, mastitis may be considered as the working diagnosis. If, however, the findings persist on follow-up mammogram after antibiotic treatment, the diagnosis is inflammatory carcinoma unless proven otherwise. At that point the patient should have a punch biopsy. Punch biopsy will often demonstrate tumor cells invading the dermal lymphatics and will confirm the diagnosis of inflammatory carcinoma. Although breast MRI may reveal the dominant mass, it is not the most cost-effective step in diagnosis. Returning the patient to annual screening mammography is only appropriate when a mammogram is clearly negative or benign and should not be recommended in this setting. Even if a dominant mass were not present and one suspects a benign entity like mastitis, follow-up should be recommended after treatment to exclude an underlying malignancy.