CASE 51
History: An asymptomatic woman presents for routine screening mammogram.
1. What should be included in the differential diagnosis based on the images shown? (Choose all that apply.)
A. Multiple bilateral fibroadenoma
B. Multiple bilateral cysts, with a suspicious mass in the upper left breast
D. Multiple bilateral complicated cysts
2. What is the next step in management of this patient?
A. Recall for bilateral ultrasound
C. Routine screening mammogram in 1 year
3. What is the cancer rate in women with bilateral circumscribed masses?
A. Slightly higher than the national average because of proliferative change
B. Approximately double the normal rate
C. Approximately the same as the normal population
D. Slightly higher, unless the cysts are palpable
4. What is the BI-RADS (Breast Imaging Reporting and Data System) for this finding on a baseline mammogram?
ANSWERS
CASE 51
Changing Pattern of Multiple Bilateral Masses
1. A, C, and D
2. C
3. C
4. A
References
Berg WA, Campassi CI, Ioffe OB. Cystic lesions of the breast: sonographic-pathologic correlation. Radiology. 2003;227(1):183–191.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:137. 381
Comment
The simple cyst is a round or oval space, filled with fluid and lined by epithelium. It is the most common mass in the female breast and has no malignant potential. It develops and regresses spontaneously, and cysts may increase when estrogens are taken.
On mammography, simple cysts are usually round or oval but may be lobulated and are typically water density, the same as the surrounding parenchyma. They are often multiple and bilateral. Although a cyst cannot be differentiated from a solid mass on mammography, the presence of multiple bilateral circumscribed masses can be considered benign. There should be at least three circumscribed or partially circumscribed masses, with at least one in each breast, to be considered a benign finding. There should be no suspicious findings, such as distortion or suspicious microcalcifications. The masses are most commonly cysts or fibroadenomas. When the masses change in size, location, and number on successive mammograms, they can be considered cysts (see the figures). Ultrasound is not needed if the patient is asymptomatic and all of the above-mentioned conditions are met. The rate of malignancy in a large study of women with bilateral circumscribed masses was approximately 0.1%, lower than the incident rate of breast cancer in the normal age-matched population. If one mass is disproportionately larger or denser or has poorly defined margins, the patient should be recalled.
This patient with bilateral, similar, circumscribed masses is at no increased risk of malignancy, and her mammogram is benign, BI-RADS 2. Assigning the patient to a BI-RADS 3 category, with short-interval follow-up, is unnecessary.
CASE 52
History: A 21-year-old woman presents with two palpable masses in her left breast—one in the upper outer quadrant and one in the lower outer quadrant.
1. What should be included in the differential diagnosis for the two ultrasound images shown? (Choose all that apply.)
A. Suspicious mass in the lower outer breast
B. Simple cyst in the upper outer breast
C. Rib in the lower outer breast
D. Fibroadenoma in the lower outer breast
2. How is a rib distinguished from a breast mass on ultrasound?
A. The rib is posterior to the chest muscle.
B. The breast mass should be posterior to the chest muscle.
C. The rib never looks oval, and masses are often oval.
D. Masses are typically more hypoechoic than the rib.
3. What is the BI-RADS (Breast Imaging Reporting and Data System) code for the ultrasound examination of this patient?
4. How reliable is the negative ultrasound examination when evaluating a palpable mass?
A. Not reliable—a mammogram must be performed for more complete evaluation.
B. Not reliable—the patient must be seen by a surgeon for consideration for biopsy.
C. Relatively reliable—the radiologist may correlate the palpable finding with the ultrasound.
D. Somewhat reliable—the patient should return for a short-interval follow-up.
ANSWERS
CASE 52
Ultrasound of Rib
1. B and C
2. A
3. C
4. C
References
Dennis MA, Parker SH, Klaus AJ, et al. Breast biopsy avoidance: the value of normal mammograms and normal sonograms in the setting of a palpable lump. Radiology. 2001;219(1):186–191.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:100. 150, 175
Comment
Patients often present with a palpable finding. They may note cysts (see the figures), solid masses, or normal parenchyma. Patients may confuse normal anatomy with pathology; the normal rib may be perceived as a mass. Ultrasound is an important tool in the evaluation of a breast lump because the area of concern can be addressed in a precise manner. One method of evaluating the lump is to place your finger or a cotton-tipped swab over the lump, as pointed out by the patient. Apply the ultrasound transducer to the finger or swab, then withdraw the finger and scan directly underneath.
The beginner ultrasonographer may confuse the rib in cross section with a breast mass (see the figures). To differentiate the rib from a breast mass, note the position of the finding relative to the pectoralis muscle, note the periodicity of the ribs, and note that turning the transducer 90 degrees elongates the rib.
CASE 53
History: A 55-year-old woman presents for a screening mammogram. Her last mammogram was obtained 4 years ago and is available for comparison.
1. What should be included in the differential diagnosis for the finding in the right breast? (Choose all that apply.)
B. Pseudoangiomatous stromal hyperplasia
D. Asymmetric glandular tissue
2. What is the BI-RADS (Breast Imaging Reporting and Data System) category?
3. Which of the following imaging tools is inadequate for further work-up?
A. Additional mammographic views
4. Which of the following statements regarding focal asymmetry is false?
B. It is not a very rare finding on screening mammogram.
C. A new focal asymmetry requires further work-up.
D. Biopsy is useful in differentiating a benign from a malignant process.
ANSWERS
CASE 53
Developing Asymmetry
1. A, B, and D
2. A
3. D
4. A
References
Leung JW, Sickles EA. Developing asymmetry identified on mammography: correlation with imaging outcome and pathologic findings. AJR Am J Roentgenol. 2007;188(3):667–675.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:410.
Comment
The breasts are usually fairly symmetric in density and architecture. Nevertheless, asymmetries are not an unusual finding on routine mammogram (see the figures), reportedly seen in 3% of healthy women. According to the BI-RADS lexicon, asymmetric findings constitute an area of tissue with fibroglandular density that is more extensive in one breast compared with the corresponding region of the contralateral breast. Asymmetries are planar, lack convex borders, usually contain interspersed fat, and lack the conspicuity of a three-dimensional mass.
There are three types of asymmetric findings: global asymmetry, focal asymmetry, and developing asymmetry. Global asymmetry involves a large portion of the breast (at least a quadrant), focal asymmetry corresponds to a density with similar shape in two views but lacking convex outward borders, and developing asymmetry is focal asymmetry that is new or increasing. A developing asymmetry may be a normal variant but can also constitute a sign of malignancy and must be viewed with caution and evaluated thoroughly.
It is important to review all previous mammograms, with at least a 2-year interval, because an area of increasing density may not be apparent over a shorter interval (see the figures). If the previous mammograms are at a different site, there is value in obtaining them. If the area is stable compared with prior films, no further work-up is needed. However, a new, larger or denser asymmetry and a palpable abnormality require additional evaluation. Additional mammographic views help to determine if the tissue spreads out or if there is interspersed fat, which is a benign feature. Additional views may include spot compression views, rolled craniocaudal views, and a true lateral view.
Ultrasound is a very good tool for evaluating focal asymmetries. The classic ultrasound appearance of an island of normal breast tissue is that of a hyperechoic area with ducts coursing through. There should be no mass, distortion, or abnormal shadowing.
A core biopsy can be performed if concern is expressed by the patient or if the asymmetry is palpable. The histology is often benign breast tissue, stromal fibrosis, or pseudoangiomatous stromal hyperplasia. MRI can be done instead of needle biopsy, although the role of MRI for assessment of asymmetric breast findings has not yet been established. With administration of contrast material, the enhancement of the asymmetric tissue should be the same as that of the rest of the glandular tissue, with no abnormal enhancement.
CASE 54
History: A 61-year-old woman of normal risk palpated a tiny mass just below her right nipple. Mammogram views of the right breast are shown.
1. What is the differential diagnosis of the mammogram of the right breast? (Choose all that apply.)
A. There is a suspicious mass near the nipple at the 6 o’clock position.
B. There is no suspicious finding.
D. Suspicious clustered microcalcifications are seen near the nipple.
2. What is the next step in the management of this patient?
A. The mammogram is normal, so she can return in 1 year.
B. The patient should seek a surgical consultation, because the mammogram is abnormal.
C. The patient should be evaluated with ultrasound of the palpable mass.
D. The patient should be asked to return in 6 months.
3. How accurate is the normal mammogram in the setting of a palpable mass?
B. Not very accurate: 20% to 40%
C. The accuracy depends on the glandular density.
D. The mammogram is nearly 100% accurate in the patient with a dense breast.
4. What should be the next step if ultrasound reveals a simple cyst at the palpable area?
A. All palpable cysts must be aspirated.
B. All simple cysts should be referred to a surgeon for excision or aspiration.
C. All simple cysts should be followed with an ultrasound exam in 6 months.
ANSWERS
CASE 54
Importance of Ultrasound in a Palpable Mass
1. B
2. C
3. C
4. D
References
Berg WA, Gutierrez L, Ness Aiver MS, et al. Diagnostic accuracy of mammography, clinical examination, US, and MR imaging in preoperative assessment of breast cancer. Radiology. 2004;233(3):830–849.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:100. 137
Comment
Patients often present with a palpable mass noted either on self-exam or on a clinician’s exam. The mammogram is not a perfect study for the detection of cancer. A 10% false-negative rate is published, based on early studies (Seidman et al, 1987). Depending on the density of the breast tissue, the false-negative rate may be higher. Conversely, when the breast is entirely fatty, the mammogram has a very low false-negative rate. If a patient presents with a palpable finding, and the mammogram shows glandular density in the area (see the figures), then a mass may be obscured by the surrounding gland tissue, and ultrasound should be performed. In this case, the patient failed to mention the palpable concern to the technologist before the mammogram views were performed, so no marker was placed to locate the site of concern. The patient decided to mention the concern after the views, and the exam was converted from screening to diagnostic because of the concern.
Ultrasound was performed (see the figures) and demonstrates a tiny mass in the subcutaneous tissues inferior to the nipple. The mass is indeterminate for the presence of malignancy. Although it is roughly oval and wider than tall (both benign features), the borders are microlobulated. This is a suspicious feature, and the presence of one suspicious feature means that biopsy should be performed. Needle core biopsy was performed with ultrasound guidance, and histology was invasive mammary carcinoma with duct and lobular features.
Ultrasound should be performed in the setting of the normal mammogram and a palpable mass. The ultrasound should be correlated with a physical exam, while scanning, to ensure that the palpable concern is evaluated. If ultrasound demonstrates a simple cyst, no further work-up is needed. A simple cyst on ultrasound is anechoic, with imperceptible walls, a sharp back wall, and increased through transmission posteriorly. If a complex cyst is seen (mass within the cyst, or cyst with irregular, thickened wall), then biopsy should be performed. If a solid mass is seen, biopsy is typically performed, particularly if there is a suspicious feature on ultrasound, such as in this patient.
CASE 55
History: A 38-year-old woman who feels a lump in the right upper outer breast undergoes a baseline mammogram.
1. What should be included in the differential diagnosis for the images shown? (Choose all that apply.)
A. Focal masslike density in the right breast on mammogram and normal ultrasound
B. Normal mammogram and ultrasound
C. Normal mammogram and dense, focal fibrosis on ultrasound
D. Dense glandular tissue on mammogram with fibrous ridge on ultrasound
2. What is the negative predictive value of a normal mammogram and normal ultrasound in the setting of a palpable mass?
A. The negative predictive value is less than 50%.
3. What is the management of this patient after normal standard imaging?
B. The patient should be referred for mandatory surgical evaluation.
C. Needle biopsy of the echogenic tissue seen on ultrasound should be offered.
4. What is the BI-RADS (Breast Imaging Reporting and Data System) of this study?
D. BI-RADS 5—highly suspicious
ANSWERS
CASE 55
Predictive Value of Negative Imaging
1. B, C, and D
2. C
3. A
4. A
References
Dennis MA. Breast biopsy avoidance: the value of normal mammograms and normal sonograms in the setting of a palpable lump. Radiology. 2001;219(1):186–191.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:174.
Comment
When a patient older than 30 years presents with a palpable finding, a mammogram should be performed as the initial study. Ultrasound is particularly helpful in the setting of a normal dense mammogram, with no evidence of a mass or suspicious microcalcifications (see the figures). Ultrasound may reveal an occult mass or cyst or may be normal. A normal mammogram and normal ultrasound in a patient who feels a lump are quite common. Often the reason for the palpable finding can be seen on ultrasound as an isolated dense, echogenic area surrounded by fat or a dense ridge (see the figures). The dense tissue is adenosis or fibrosis but is a normal variation and should be communicated as such to the patient and the referring physician.
Several studies have shown that the positive predictive value of a negative mammogram and negative ultrasound in the setting of a palpable finding is nearly 100%. The normal findings are reliable, the report is given a BI-RADS 1, and no imaging follow-up is needed. The patient and the physician may choose to follow up with a surgical consultation based on clinical grounds alone.
It is important that the radiologist personally correlate the clinical and imaging findings in this situation. The technologist performing the ultrasound may miss a subtle finding or may believe that the clinically apparent lump is quite suspicious on palpation. If the clinical finding is suspicious, and no abnormality is seen on standard imaging, MRI can be performed to evaluate further.
CASE 56
History: A 66-year-old woman presents with a palpable mass in her left breast, 6 weeks after a screening mammogram that was interpreted as normal.
1. What should be included in the differential diagnosis for the three mammogram images shown? (Choose all that apply.)
A. Rapid growth of a breast malignancy
B. Abscess developing in left breast
C. Benign mass was excised; mass represents palpable surgical site
D. Rapid growth of a benign fibroadenoma
2. Why are cancers missed at screening mammography?
A. The breast tissue is fatty.
B. The missed cancer is spiculated and associated with calcifications.
C. The radiologist incorrectly interpreted the mammogram.
D. There are prior mammograms for comparison.
3. What is an interval cancer?
A. A cancer that develops between routine screening examinations
B. A cancer that is intermediate grade
C. A cancer that develops in a woman who has a family history of breast cancer in her daughter
D. A cancer that develops in the same breast as cancer was diagnosed earlier
4. What are “minimal signs” or “nonspecific signs” on mammography?
A. A visible lesion on mammogram, not worrisome enough to warrant recall
B. Tissue density that is 25% to 50% dense
C. Lesions that are suspicious for malignancy
D. Secondary signs of malignancy, such as skin thickening
ANSWERS
CASE 56
Interval Cancer
1. A, B, and C
2. C
3. A
4. A
References
Cho N, Kim SJ, Choi HY, et al. Features of prospectively overlooked computer-aided detection marks on prior screening digital mammograms in women with breast cancer. AJR Am J Roentgenol. 2010;195(5):1276–1282.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:408.
Comment
An interval cancer is one that is detected between routine screening mammograms. It is typically found on clinical examination by the patient’s physician at a routine clinical visit or felt by the patient on breast self-examination. The incidence of interval cancer relates to the sensitivity of mammography, which is variably reported as 80% to 90%—that is, some cancers are missed on mammography, no matter how skilled the radiologist.
When the patient presents with a clinical finding, and the previous screening mammogram is reviewed, a suspicious lesion may be seen that was clearly overlooked by the interpreting radiologist. This situation may be due to a perception error or a misinterpretation error. A smaller percentage of findings on the previous screen are termed “minimal” or “nonspecific,” meaning that although a lesion is present, it does not meet the threshold for recall. It may be low density, with smooth margins, as in the patient in this case (see the figures). Other cases are truly occult on the previous screening mammogram and are typically aggressive, rapidly growing tumors (see the figures).
Several studies have shown that women with interval cancers have higher stage disease and more often have positive lymph nodes compared with women with cancers detected on screening examination. Interval cancers are more often well-defined masses, which are uncommon and which may have a nonspecific appearance, such as the special types of infiltrating ductal carcinoma, including medullary, mucinous, invasive papillary, and tubular cancers. This patient had the much more common infiltrating ductal carcinoma, not otherwise specified, grade II/III. She had a positive axillary lymph node.
To attempt to reduce the number of overlooked cancers, the radiologist should be alert to subtle changes in lesions, including change in size or density (see the figures), and should judge a lesion by its most suspicious feature.
CASE 57
History: Two patients present for routine screening mammography. The first figure shows the left mammogram in a 40-year-old asymptomatic woman. The second figure shows the magnification views performed as additional views after routine mammogram in a 58-year-old asymptomatic woman.
1. What should be included in the differential diagnosis for the two patients shown? (Choose all that apply.)
A. Lobular carcinoma in situ (LCIS)
D. Ductal carcinoma in situ (DCIS)
2. What are the descriptive terms used for the calcifications in patient 1?
A. Coarse, heterogeneous, and segmental
C. Coarse, linear, and rodlike
D. Clusters of punctate calcifications
3. What are the descriptive terms used for the calcifications in patient 2?
A. Snakeskin, filling the ducts
C. Fine, linear, and branching
4. Why is it important to recognize the location of calcifications within the breast?
A. Calcifications not in ducts, lobules, or masses are typically benign.
B. Calcifications in ducts are almost always malignant.
C. Calcifications in masses are typical of fibroadenoma.
D. Calcifications in lobules are typical of LCIS.
ANSWERS
CASE 57
Ductal Carcinoma In Situ
1. C and D
2. A
3. C
4. A
References
Evans A. The diagnosis and management of pre-invasive breast disease: radiological diagnosis. Breast Cancer Res. 2003;5(5):250–253.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:64.
Comment
Mammography is the primary tool for the detection and biopsy of DCIS. Calcifications develop in ducts and have characteristic appearances. Calcifications are present in 80% to 90% of cases of DCIS that have a mammographic abnormality (see the figures). The remaining 10% to 20% of cases manifest as a noncalcified mass or developing asymmetric density.
DCIS is classified as low grade, intermediate grade, and high grade. The histopathologist uses the terms comedocarcinoma, micropapillary, solid, and cribriform to describe the DCIS architecture on histology. The individual calcifications form in the necrotic portions of the intraductal tumor. The shapes of calcifications are termed pleomorphic, fine linear, and branching (see the figures); coarse and fine heterogeneous or granular (see the figures); amorphous; and indistinct. The term pleomorphic means the calcifications within the group vary in shape, size, and density, which is common in DCIS. The distribution of the calcifications is very important. Terms for DCIS distribution include clustered, linear, and segmental. The first figure shows segmental distribution, and the second shows clustered distribution.
In the assessment of breast calcifications, it is important to consider the worst-appearing calcifications within the group. In the second figure, there are some punctate forms, which are typical of benign fibrocystic change. This patient’s histology report described cancerization of the lobules. In cancerization, tumor spreads from the duct into the adjacent lobules and forms calcifications in lobules, which are typically punctate. In this cluster, the fine linear branching calcification is highly suspicious for DCIS. The presence of the punctate calcifications should not rule out classifying this cluster as suspicious.
It is impossible to predict definitely the subtype of DCIS based on the shape and distribution of the calcifications; however, the coarse heterogeneous pattern seen in patient 1 is often seen in micropapillary type with necrosis, which was her histology. Patient 2 had a high–nuclear grade solid and cribriform pattern, with extension into lobules, which is commonly seen in the fine linear branching form of DCIS.
CASE 58
History: A 58-year-old woman presents for screening mammogram.
1. What is the differential diagnosis, based on the images presented? (Choose all that apply.)
C. Focal density on MLO view only, possible mass
D. Without prior films, there is no way to give a diagnosis
2. What is the next step of the work-up?
A. Do a 90-degree lateral mediolateral (ML) view.
B. Do a rolled craniocaudal (CC) view.
C. Do an ultrasound of the entire breast, looking for a mass.
D. Do an MRI, looking for an enhancing lesion.
3. You do a 90-degree mediolateral (ML) view next. Why?
A. To see if the image is a real lesion or is caused by overlapping normal structures
B. To identify the location of the density in the medial or lateral breast
C. To include more lateral breast tissue in the image
D. To determine if the density is more likely a lymph node
4. What is “triangulation”?
A. The process of eliminating an image you think is not a real lesion
C. Finding a mass in the lateral aspect of the breast not included on the CC view
D. Using ultrasound to help find a mass seen only on one view
ANSWERS
CASE 58
Mass Seen on One View
1. B and C
2. A
3. B
4. B
References
Sickles EA. Practical solutions to common mammographic problems: tailoring the examination. AJR Am J Roentgenol. 1988;151:31–39.
Sickles EA. Breast imaging: from 1965 to the present. Radiology. 2000;215:1–16.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:49.
Comment
This asymptomatic patient presented for a routine mammogram. Not shown are her prior mammograms, which are negative. The focal density in the upper posterior left breast is a new finding. However, even in the absence of old films, this focal asymmetric density must be viewed with suspicion. Even though it is seen on only one view, it is no less suspicious. Its location in the posterior breast means that it might not have been included on the CC view, even though the CC view appears adequate for interpretation.
The way to determine the location of the lesion is to find it on two orthogonal views. The true lateral view is orthogonal to the CC view. The location of the density on the true lateral view is helpful in locating the lesion in two ways: It gives the distance from the nipple in the vertical plane, and by comparing the two views, the MLO and the true lateral, you can determine the location of the lesion in the breast, either medial or lateral to the nipple. This is well illustrated in the article by Dr. Sickles in 1988. If the lesion is more cephalad on the ML view, compared to the MLO view (goes up), it is in the medial breast. If it is more caudal on the ML view compared to the MLO view, it is in the lateral breast. This process is termed triangulation and can be visually demonstrated by lining up three views of the same breast in the order ML, MLO, CC, with the nipples at the same level and pointing the same way. A line drawn between the lesion on the two views predicts the location in the third view.
In this patient, the lesion is in the upper breast on the MLO view (see the figures) and is located more cephalad in the breast on the ML view (see the figures). Thus, you can determine that it is a medial lesion and instruct the technologist to perform a CC view, exaggerated to the medial aspect. This specialized view is shown in the fourth figure. The lesion is seen, and it can now be determined to be a true mass, located in the upper inner aspect of the left breast, at about the 10 o’clock position. The distance from the nipple in the vertical plane can be determined from the ML view, and the distance from the nipple in the radial plane can be determined from the exaggerated medial CC (XCCM) view. The next step would be to perform an ultrasound of the left 10 o’clock location to find the mass, assess its characteristics, and target the lesion for biopsy. MRI is typically used after a diagnosis of cancer has been made, in order to evaluate extent of disease, because additional masses may be missed on the mammogram.
CASE 59
History: A 42-year-old woman presents with a palpable mass in her left breast.
1. What should be included in the differential diagnosis, based on the images provided? (Choose all that apply.)
A. Malignant mass with ductal carcinoma in situ (DCIS) extending toward nipple
B. Phyllodes tumor with adjacent DCIS
C. Simple cyst and benign calcifications
D. Malignant mass with benign calcifications
2. What is an extensive intraductal component?
A. Malignancy that contains a large proportion of DCIS
B. Purely intraductal carcinoma
C. DCIS and atypical ductal hyperplasia
D. A long segment of DCIS involving the entire quadrant of the breast
3. What mammographic features suggest an extensive intraductal component?
B. A cluster of microcalcifications less than 1 cm in diameter
D. Mass with microcalcifications in an area greater than 3 cm
4. Which of the following statements is not true about calcifications adjacent to a suspicious mass?
A. Unless the calcifications are recognized and removed, the patient’s risk of recurrence is higher.
C. The size of the tumor in the breast affects staging.
ANSWERS
CASE 59
Extensive Intraductal Component
1. A, B, and D
2. A
3. D
4. B
References
Stomper PC, Connolly JL. Mammographic features predicting an extensive intraductal component in early-stage infiltrating ductal carcinoma. AJR Am J Roentgenol. 1992;158(2):269–272.
Cross-Reference
Ikeda D. Breast Imaging. In: THE REQUISITES. 2nd ed Philadelphia: Saunders; 2010:95.
Comment
An extensive intraductal component is a histologic feature that is associated with a higher recurrence rate after breast conservation therapy. In studies in which the tumor was excised, without regard to evidence of DCIS at the margins, 24% of patients had recurrence of their cancer after treatment compared with 6% of patients who had histologically benign margins. Radiation therapy at the accepted dose may be inadequate to treat the residual tumor. It is important to recognize when an extensive intraductal component may be present to guide the treating physician to excise all the malignant tissue before radiation.
Microcalcifications, in particular, when they extend from the tumor in linear distribution at least 3 cm, are the mammographic feature most commonly associated with an extensive intraductal component. Studies show that the proportion of infiltrating ductal carcinomas with an extensive intraductal component is approximately 25% to 35%, so evaluation of the mammogram with a suspicious mass for adjacent calcifications is prudent (see the figures).
MRI is also useful for evaluation of an extensive intraductal component. Linear enhancement, long spicules, a regional enhancing area, and nodules adjacent to a mass are suspicious MRI findings for an extensive intraductal component (see the figures). In one more recent study, MRI was shown to be superior to the mammogram in predicting an extensive intraductal component and assessing total tumor size.
This patient presented for baseline mammogram at age 42 with a palpable mass in the left breast. Microcalcifications were recognized in the same quadrant as the mass and extending toward the nipple in segmental distribution. She underwent image-guided biopsy of both the mass and the calcifications that were seen farthest away from the mass to establish the extent of disease. The mass was invasive ductal carcinoma, grade III, and the calcifications were DCIS, grade III.
If breast conservation therapy is desired in patients with an extensive intraductal component, bracketing the location of calcifications is necessary at the time of needle localization to include all of the suspected and known disease in the lumpectomy specimen. A mammogram after surgery is helpful to assess the complete excision of all suspicious calcifications before radiation therapy.
CASE 60
History: A 43-year-old woman presents for routine screening mammogram. She had an excisional biopsy in her left axilla 3 years previously with benign findings.
1. What should be included in the differential diagnosis of the more recent mammogram? (Choose all that apply.)
A. Ectopic breast tissue in the left axilla
B. Spiculated suspicious mass in the left axilla
C. Supernumerary breast in the left axilla
2. What is the clinical concern regarding ectopic gland tissue?
A. Malignancy is more common in ectopic locations.
B. Malignancy can occur in ectopic breast tissue.
C. The concern is primarily cosmetic.
D. Malignancy in the axilla is much more likely to become metastatic.
3. Which of the following statements is not true about the “milk line”?
A. It is an area where primordial rests of breast tissue are present.
B. It relates to animals, not humans.
D. Accessory nipples occur along this line.
4. What is the one best diagnosis of the mammogram and ultrasound from 3 years previously?
D. Left axillary complex cystic mass
ANSWERS
CASE 60
Ectopic Tissue
1. A and C
2. B
3. B
4. C
