Breast Imaging: A Core Review (14 page)

^a
Evidence from nonrandomized screening trials and observational studies.

Based on evidence of lifetime risk for breast cancer.

2
 
Answer B.
Sternalis muscle is a normal variant of an anatomic chest wall musculature. It is located medially adjacent to the sternum and is seen only on the CC mammogram medially. It is present in both males and females.

Reference: Berg A, Birdwell R, Gombos E.
Diagnostic Imaging Breast
. 1st ed. Salt Lake City, UT: Amirsys; 2008:IV:3:40–41.

3a
 
Answer A.

3b
 
Answer B.
Although these calcifications appear suspicious on the provided screening mammogram, it is important to remember the steps required in the workup of an abnormality seen at screening. BI-RADS 0, incomplete, is the appropriate first step in diagnosis. The patient can then return for additional views. These calcifications are highly suspicious; thus, the term “pleomorphic fine linear branching” is the best answer for description. Stereotactic or surgical biopsy should be recommended.

Reference: Kopans D.
Breast Imaging
. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006:530–543.

4
 
Answer B.
The important findings to detect in this case include a bilateral increase in breast density, loss of fat, and decrease of breast size. The differential diagnosis for increased breast density includes hormone replacement therapy, endogenous hormonal stimulation such as in pregnancy and lactation, bilateral breast edema such as from congestive heart failure, bilateral breast trauma, weight loss, and bilateral inflammatory breast cancer. Of these, bilateral inflammatory breast cancer. Of these, bilateral inflammatory breast cancer is the rarest. In this case, the decreased breast size and loss of fat combined with the increased breast density are most consistent with weight loss. The patient in this case reported a 90-pound weight loss between the two studies. Hormone replacement therapy and endogenous hormonal stimulation are typically associated with increased breast size.

Reference: Berg WA, Birdwell RL, eds.
Diagnostic Imaging: Breast
. Salt Lake City, UT: Amirsys; 2008;IV:5-48–IV:5–49.

5
 
Answer B.
This is an example of a mammogram in a woman who has had a previous bilateral reduction mammoplasty. The nipple is elevated because there is more skin inferior to the nipple than superior to the nipple. In these cases, the residual fibroglandular breast tissue is redistributed from the upper outer quadrant to the inferior inner quadrant to replace the tissue that was removed. This creates a swirled fibroglandular tissue pattern in the inferior inner quadrant. The calcifications associated with fat necrosis are visible mammographically; later, they are seen in only 50% of cases by 2 years after the surgery.

Reference: Berg WA, Birdwell RL, eds.
Diagnostic Imaging: Breast
. Salt Lake City, UT: Amirsys; 2008;IV:4-32–IV:4–35.

6
 
Answer A.
Carriers of the BRCA1 or BRCA2 mutation should begin annual routine screening mammography at age 30 years. Women with mothers or sisters with breast cancer should begin annual routine screening at age 30 (but not before age 25) or 10 years earlier than the age of their relatives’ diagnosis, whichever is later. In this case, if the patient was not a BRCA2 mutation carrier she would have begun screening at age 35 based on her mother’s history and at age 32 based on her sister’s history. Forty is the age when women who do not have an increased risk of breast cancer to begin screening.

Reference: Lee CH, Dershaw DD, Kopans D, et al. Breast cancer screening with imaging: Recommendations from the Society of Breast Imaging and the ACR on the use of mammography, breast MRI, breast ultrasound, and other technologies for the detection of clinically occult breast cancer.
J Am Coll Radiol
2010;7:18–27.

7
 
Answer A.

B.
 MRI is recommended in women with >20% lifetime risk for breast cancer on the basis of family history.

C.
 Women with a history of chest irradiation should begin screening MRI 8 years after the completion of radiation therapy, not necessary at age 30.

D.
 Women with a history of biopsy-proven ADH should be considered for screening MRI only if other factors make their overall lifetime risk between 15% and 20%.

Reference: Lee CH, Dershaw D, Kopans D, et al. Breast cancer screening with imaging: Recommendations from the society of breast imaging and the ACR on the use of mammography, breast MRI, breast ultrasound, and other technologies for the detection of clinically occult breast cancer.
J Am Coll Radiol
2010;7:18–27.

8
 
Answer E.
The positive predictive value (PPV) of biopsy will be increased because of a substantial reduction in the number of interventional procedures that produce benign results.

A.
 Periodic mammographic surveillance does not affect call-back rates.

B.
 Operating costs will decrease substantially because (1) the cost of diagnostic examinations usually is much lower than that of imaging-guided interventional procedures and (2) surveillance adds cost only to the extent that it requires examinations in between those performed for routine screening, which for most follow-up protocols involves only one additional examination.

C.
 False-positive results will be reduced, similar to increase in PPV, due to reduction of the number of interventions that produce benign results.

D.
 Surveillance is associated with reduced morbidity, especially when compared to open surgical biopsy but also when compared to percutaneous imaging-guided tissue sampling.

Reference: Sickles EA. Probably benign breast lesions: when should follow-up be recommended and what is the optimal follow-up protocol?
Radiology
1999;213:11–14.

9
 
Answer A.
According to BI-RADS manual, lesions appropriately placed in BI-RADS category 3 include a nonpalpable, circumscribed mass on a baseline mammogram (unless it can be shown to be a cyst, an intramammary lymph node, or another benign finding), a focal asymmetry that partially thins on spot compression, and a cluster of round punctate calcifications. Answer choices B, D, and E should be given a BI-RADS 0 category assessment and be called back for additional imaging, and if persist, undergo biopsy. Answer choice C is a benign lesion.

Reference: American College of Radiology (ACR).
BI-RADS Mammography: Guidance Chapter
.
Reston, VA: American College of Radiology; 2012:254–255.

10
 
Answer B.
Computer-aided detection (CAD) mammography increases breast cancer detection rate ~7% to 20%.

A.
 CAD sensitivity is greater for calcifications than masses.

C.
 Use of CAD increases the recall rate by about 8.2%.

D.
 CAD is to provide “spell check” while looking at screening mammograms, after independent or unaided case assessment by radiologist. It is not a primary tool in reading mammograms.

E.
 CAD makes about 2.0 false marks per every four-view negative mammogram. However, with experience, overwhelming majority of false CAD marks are readily dismissed.

Reference: Birdwell RL, Bandodkar P, Ikeda DM. Computer-aided detection with screening mammography in a university hospital setting.
Radiology
2005;236:451–457.

11
 
Answer E.
Known risk factors of male breast cancer include advance age, Klinefelter syndrome, BRCA2, family history, obesity, treatment with estrogen for prostate cancer, excess alcohol consumption, head trauma resulting in increased prolactin production, and testicular diseases such as undescended testes, orchiectomy, mumps orchitis, and testicular injury.

A.
 Gynecomastia is not considered a risk factor for male breast cancer by most authorities.

B.
 Male breast cancer is <1% of all male cancers in the United States, and 0.2% to 0.9% of breast cancers in the United States.

C.
 Female relatives of men with breast cancer have increased risk of breast cancer equivalent to increased risk with female breast cancer.

D.
 Approximately 18% to 33% of male breast cancer patients have BRCA2 gene mutation.

Reference: Berg WA, Birdwell RL, eds.
Diagnostic Imaging: Breast
. Salt Lake City, UT: Amirsys; 2006:IV:5:54–57.

12
 
Answer A.
Invasive ductal carcinoma is the most common type of breast cancer in both women and men. Since breast cancer in women and that in men are indistinguishable histologically, all ductal subtypes of breast cancer (including medullary and mucinous) have been described in men. Most male breast cancers are detected when they are still intraductal.

B.
 Invasive lobular carcinoma is an uncommon type of breast cancer in men because lobule formation in men is rare.

C.
 Paget disease of the nipple makes up about 12% of all male breast cancers. It is considered a carcinoma in situ involving the nipple epidermis, and the malignant cells extend through the ducts.

D.
 Atypical ductal hyperplasia (ADH) is a high-risk lesion that increases the risk for developing invasive breast cancer by four to five times. Twenty-two percent of male breast cancer (invasive carcinoma) has associated ADH.

References: Berg WA, Birdwell RL, eds.
Diagnostic Imaging: Breast
. 1st ed. Salt Lake City, UT: Amirsys; 2006:IV:5:54–57.
Kopans DB.
Breast Imaging
. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:675–676.

13
 
Answer C.
BI-RADS 3 is used for findings that are almost certainly benign, with <2% chance of malignancy. Additional mammographic views and/or ultrasound is required to evaluate abnormalities discovered on a screening mammogram before an assessment of BI-RADS 3 is assigned. These findings are reassessed in the short term with the initial follow-up period, usually at 6 months.

A.
 BI-RADS 0, incomplete. This category can be used to recall a patient for additional views or if retrieval of prior films is required.

B.
 BI-RADS 1 is used when the screening mammogram is negative, and there is no evidence to suggest malignancy.

D.
 BI-RADS 5 is used for lesions that are almost certainly breast carcinoma with classic features present. These lesions have a >95% chance of malignancy. The recommendation is to obtain histologic diagnoses by biopsy.

Other BI-RADS assessment categories:
BI-RADS 2 is used as a “normal” assessment of the screening mammogram like category 1, but the interpreter may choose to describe a completely benign finding.

BI-RADS 4 is used for a “suspicious abnormality,” when a finding does not demonstrate classic malignant characteristics but has a probability of malignancy that is greater than category 3 (>2%). Category 4 can be subdivided into 4A-low suspicion, 4B-intermediate suspicion, or 4C-high suspicion, which can guide the decision for plan of action.

BI-RADS 6 is used when there is an imaging finding that is already biopsy proven to be a malignancy but prior to definitive therapy.

Reference: American College of Radiology (ACR). ACR BI RADS—Mammography. In:
ACR Breast Imaging Reporting and Data System, Breast Imaging Atlas
. 4th ed. Reston, VA: American College of Radiology; 2003:194–197.

14
 
Answer D.
 There are multiple neurofibromas consistent for neurofibromatosis type 1 (NF1). NF1 is associated with Lisch nodules (hamartomas of iris), freckling in the iris. NF2 is associated with bilateral acoustic neuromas, increased risk for meningiomas, and ependymomas.

Reference: Brant WE, Helms CA.
Fundamentals of Diagnostic Radiology.
3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:233–237.