Breast, Abnormal Mammogram Case File
Eugene C. Toy, MD, Patti Jayne Ross, MD, Benton Baker III, MD, John C. Jennings, MD
CASE 48
A 59-year-old woman comes into the doctor’s office for a health maintenance examination. Her past medical history is remarkable for mild hypertension controlled with an oral thiazide diuretic agent. Her surgical history is unremarkable. On examination, her blood pressure is 140/84 mm Hg, heart rate is 70 beats per minute, and she is afebrile. The thyroid is normal to palpation. The breasts are nontender and without masses. The pelvic examination is unremarkable. Mammography revealed a small cluster of calcifications around a small mass.
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ANSWER TO CASE 48:
Breast, Abnormal Mammogram
Summary: A 59-year-old woman comes into the doctor’s office for a health maintenance examination. The breasts are nontender and without masses. Mammography revealed a small cluster of calcifications around a small mass.
- Next step: Stereotactic core needle biopsy.
ANALYSIS
Objectives
- Understand the role of mammography in screening for breast cancer.
- Know that mammography is not perfect in identifying breast cancer.
- Know the typical mammographic findings that are suspicious for cancer.
Considerations
This 59-year-old woman is going to her doctor for routine health maintenance. She is taking a thiazide diuretic for mild hypertension. Her blood pressure is mildly elevated. The mammogram reveals a small cluster of calcifications around a small mass, which is one of the classic findings of breast cancer. With this mammographic finding, it is of paramount importance to obtain tissue for histologic diagnosis. Because of the high risk of malignancy, a stereotactic-directed core biopsy is indicated.
APPROACH TO:
The Abnormal Mammogram
DEFINITIONS
SUSPICIOUS MAMMOGRAPHIC FINDINGS: A small cluster of calcifications, or masses with ill-defined borders.
NEEDLE LOCALIZATION: Procedure in which a sterile wire is placed via mammographic guidance such that the end of the wire is placed in the center of the suspicious area. The surgeon uses this guide to assist in excising breast tissue.
STEREOTACTIC CORE BIOPSY: Procedure in which the patient is prone on the mammographic table and biopsies are taken as directed with computer-assisted techniques.
CLINICAL APPROACH
Although a clinical history and proper clinical breast examinations are important in detecting breast cancer, mammography remains the best method of detecting breast cancer at an early stage.
A mammogram is an x-ray of the breast tissue. Current radiation levels from mammography have been shown to be safe and cause no increased risk in developing breast cancer. The radiation exposure is < 10 rad per lifetime if annual mammograms begin at age 40 years and continue up to age 90. Both false positives and false negatives of up to 10% have been noted. Hence, a palpable breast mass in the face of a normal mammogram still requires a biopsy. Breast implants can diminish the accuracy of a mammogram, particularly if the implants are in front of the chest muscles. Magnetic resonance imaging has recently been shown to be effective in screening for breast cancer, particularly in younger patients and those at risk for breast cancer such as due to BRCA mutation. Magnetic resonance imaging (MRI) may identify early breast cancers missed by mammography.
Mammographic findings strongly suggestive of breast cancer include a mass, often with spiculated and invasive borders, or an architectural distortion, or an asymmetric increased tissue density when compared with prior studies or a corresponding area in the opposite breast (Figure 48– 1). An isolated cluster of irregular calcifications, especially if linear and wispy, is an important sign of breast cancer.
Figure 48–1. Mammogram showing spiculated mass. Early intraductal carcinoma of the right breast.
Craniocaudal (A) and oblique mediolateral (B) views of the right breast show a spiculated mass in the
upper outer quadrant. (Reproduced with permission from Schwartz SI, Shires GT, Spencer FL, et al, eds. Principles of Surgery. 7th ed. New York, NY: McGraw-Hill; 1999:545.)
If a breast cancer is suspected, biopsy is warranted. A stereotactic biopsy may be used to localize and sample the lesion. This method employs a computerized, digital, three-dimensional view of the breast and allows the physician to direct the needle to the biopsy site. The procedure carries a 2% to 4% “miss rate.” Needle localization biopsies employ multiple mammographic views of the breast and allow the surgeon to localize the lesion for evaluation. The latter procedure is more time consuming, carries a comparable 3% to 5% miss rate, but excises more tissue, which is helpful in “borderline” histologic conditions, such as ductal carcinoma-in-situ.
As compared to conventional film mammography, digital mammography has a slightly higher sensitivity for women less than age 50, premenopausal women, and those with dense breasts. However, outside of those categories, film mammography and digital mammography have similar accuracy.
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CASE CORRELATION
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COMPREHENSION QUESTIONS
48.1 A 40-year-old woman undergoes a screening mammogram which reveals a lesion of the right breast, showing an ill-defined mass with a cluster of calcifications. She recalls bumping her right breast against a doorknob leading to a bruise approximately 1 year previously. Which of the following is the most likely diagnosis?
A. Ductal carcinoma-in-situB. Infiltrating intraductal carcinomaC. Fat necrosisD. Lobular carcinoma
48.2 A 39-year-old woman physicist is referred by her physician for a screening mammogram. She asks about the amount of radiation exposure, and the cumulative risk of cancers due to the radiation. Which of the following describes the radiation risk with modern mammography given once annually?
A. Increased risk for thyroid cancerB. No increased risksC. Increased risk for lung cancerD. Increased risk of skin cancer in the chest area
48.3 A 55-year-old woman has several coarse calcifications found on mammographythat are suspicious for breast cancer. She has no family history of breast cancer and no mass is palpable. Which of the following is the most accurate statement?
A. The best diagnostic method for this patient is fine-needle aspiration.B. The next best step is MRI of the lesion.C. Since there is no palpable mass on physical examination, the patient may be observed for changes on mammography in 3 months.D. One option for this patient is a core tissue biopsy by stereotactic means.
48.4 A 62-year-old woman is noted to have a 2-cm left breast mass detected on clinical examination. Stereotactic core needle biopsy reveals infiltrating ductal carcinoma. The patient is noted to have a triple negative tumor. Which of the following is more accurate about this condition?
A. The patient has a negative mammogram, MRI, and ultrasound.B. The patient has a negative sentinel node biopsy, chest x-ray, and computed tomography scan.C. The patient has a negative estrogen and progesterone receptor, and her2/neu expression status.D. The patient has a negative surgical margin laterally, medially, and anteroposteriorly.
ANSWERS
48.1 C. Fat necrosis resulting from trauma to the breast often leads to mammographic findings that are identical to breast cancer. For instance, trauma to the breast due to a motor vehicle accident with the shoulder belt causing bruising of the breast is a common scenario. This patient recalls trauma to
the breast in the location of the mammographic abnormality. To further evaluate the patient and confirm the diagnosis, a biopsy should be performed. Cancer is still a concern, and infiltrating ductal carcinoma is the most common histological subtype.
48.2 B. Modern mammography has very low radiation and no increased risk of cancer.
48.3 D. Mammographic findings that are suspicious for cancer must be addressed. Two viable methods include core biopsy via stereotactic guidance and needlelocalization excision. Fine-needle aspiration is not sensitive enough, and no mass is palpable to be able to serve for localizing. MRI does not add to an already suspicious lesion.
48.4 C. The triple negative malignancy consists of estrogen receptor, progesterone receptor, and her2/ neu expression negative. This finding is associated with a poor prognosis, and the malignancy is less treatable.
CLINICAL PEARLS
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» Mammographic findings suggestive of cancer include a small cluster of calcifications or a mass with irregular borders. » Stereotactic core biopsy or needle-localization excisional biopsy are two accepted methods of assessing suspicious mammographic nonpalpable masses. Core needle biopsy can decrease the number of surgical procedures for the patient. » The amount of radiation from mammography is negligible and has no significant sequelae. » Trauma to the breast may lead to fat necrosis and produce mammographic findings similar to that seen in breast cancer. These lesions should be excised to confirm the diagnosis. |
REFERENCES
American College of Obstetrician and Gynecologists. Breast cancer screening. ACOG Practice Bulletin 42. Washington, DC; August 2011. (Reaffirmed 2014.)
American College of Obstetricians and Gynecologists. Management of gynecologic issues in women with breast cancer. ACOG Practice Bulletin 126; March 2012. (Reaffirmed 2014.)
Foulkes WD, et al. Triple-negative breast cancer. N Engl J Med. 2010:363;1938.
Hacker NF, Friedlander ML. Breast disease: a gynecologic perspective. In: H acker NF, Gambone JC, Hobel CJ, eds. Essentials of Obstetrics and Gynecology. 6th ed. Philadelphia, PA: Saunders; 2015: 332-344.
Valea FA, Katz VL. Breast diseases. In: Katz VL, Lentz GM, Lobo RA, Gersenson DM, eds. Comprehensive Gynecology. 6th ed. St. Louis, MP: Mosby-Year Book; 2012:327-357.
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