Exercise: The First Mammogram(The Asymptomatic Patient)

THE ASYMPTOMATIC PATIENT

EXERCISE 5-3. THE FIRST MAMMOGRAM

5-9. According to the American Cancer Society, the best program of breast screening for this woman in Case 5-9 (Figure 5-17) includes all of the following except

A.   yearly MRI.

B.   yearly mammograms.

C.   cessation of routine mammograms at age 65.

D.   annual clinical breast examination.

5-10. The most likely diagnosis in Case 5-10 (Figure 5-18) is

A.   complex cyst.

B.   fibroadenolipoma.

C.   galactocele.

D.   ductal carcinoma.

E.   oil cyst.

5-11. The differential diagnosis in Case 5-11 (Figure 5-19) includes all of the following except

A.   invasive ductal carcinoma.

B.   cyst.

C.   intraductal comedocarcinoma.

D.   fibroadenoma.

E.   mucinous carcinoma.

Radiologic Findings

5-9. Detail of mammogram of the patient in this case shows a smoothly marginated small mass with a lucent center (arrow) (C is the correct answer to Question 5-9).

5-10. The mammogram in this case shows a circumscribed mass (arrows) with internal lucency as well as opacity (B is the correct answer to Question 5-10).

5-11. Mammogram of patient in this case shows a nodular density (arrow), with indistinct margins (C is the correct answer to Question 5-11).

Discussion

In Case 5-9, the 40-year-old woman has a strong family his-tory of breast cancer, which puts her at high risk for develop ing the disease. As was stated in the introduction to this chap-ter, controversy exists concerning when mammographic screening should be initiated and the appropriate frequency of examinations in different groups. Most experts agree, however, that patients with a strong family history will bene-fit from screening beginning at age 40. The American Cancer Society (ACS) recommends annual screening from age 40 in all female patients; therefore, B is not the correct answer.

Although the upper age limit for mammographic screen-ing has not been defined, we certainly cannot recommend cessation over age 65, because the prevalence of breast cancer is greatest in women in their 50s and 60s. Current ACS guide-lines recommend yearly mammograms for all women over the age of 40 years. Appropriate age for termination of screening is best judged by the patient’s physician, weighing life expectancy against potential benefits from screening.

ACS recommends annual screening MRI in women at high risk for breast cancer. ACS also recommends yearly physical examination by the physician to detect tumors missed by mammography, as well as those that become de-tectable between routine mammograms (interval cancers). Therefore, A and D are not correct answers to Question 5-9.

This patient’s mammogram is normal and demonstrates a typical normal lymph node. The node is smoothly mar-ginated and has a fatty hilum, indicated by the darker center.

In Case 5-10, there is a circumscribed mass in the axillary tail of this breast. The key to diagnosis is the mixture of den-sities within the lesion. There are medium-density opacities interspersed with lucencies within a smoothly marginated mass. This appearance is pathognomonic for a fibroadeno-lipoma, sometimes called by the misnomer hamartoma. Being composed of elements of normal breast (fatty, glandu-lar, and fibrous tissues) organized within a thin capsule, a fi-broadenolipoma forms a “breast within a breast.” As such, it is benign and needs no further evaluation. It may be palpable as a soft mass.

The point to remember here is that fat-containing masses are always benign. Answer D, ductal carcinoma, is incorrect. The differential diagnosis of a fatty mass, besides fibroadenolipoma, includes lymph node, as in Case 5-9, galactocele, lipoma, and oil cyst. Galactoceles are usually smaller and are most commonly seen in lactating women (Answer C is incorrect).

Oil cysts result from fat necrosis and are usually smaller. Typically, they are entirely lucent, as they are filled with oil, except for a thin wall (Answer E is incorrect).

Option A, complex cyst, is incorrect because this entity would not contain fat. A cyst, whether it contains serous fluid, blood, or pus, is always opaque and of low to high den-sity, not lucent.

In Case 5-11, an asymptomatic 45-year-old woman’s first mammogram shows a 1-cm nodule centrally located in this breast. The differential diagnosis remains broad without fur-ther studies to help characterize this nodule. All choices ex-cept option C, intraductal comedocarcinoma, may have this appearance. Intraductal carcinoma, when not mammo-graphically occult, usually appears as microcalcifications. Be-cause the margins are indistinct, however, the patient must be recalled for additional imaging to rule out carcinoma.

The sonographic image shows a solid lesion, ruling out a simple cyst. Spot compression is then used to evaluate the borders. If all margins were to appear smooth, one acceptable course of action would be serial 6-month follow-up mam-mograms for a period of 2 years to demonstrate stability. If any change occurs during this time, biopsy is indicated.

Spot compression (Figure 5-20 A) reveals that portions of the border are not smooth, raising the level of suspicion for malignancy. To exclude carcinoma, biopsy is needed.

Biopsy may be accomplished with excision or with needle biopsy. Excision would require needle localization of the nodule for the surgeon, because this is a nonpalpable lesion. Core needle biopsy, either stereotactic or ultrasound-guided, is preferable because it is minimally invasive, causes less mor-bidity to the patient, leaves no distortion in the breast or on the skin, and is often less expensive than surgical excision. Accurate needle biopsy devices, however, are expensive and are not universally available.

This nodule was diagnosed as a fibroadenoma with stereotactic core needle biopsy (Figure 5-20 B). Fibroadeno-mas are very common and are frequently the cause of benign breast biopsy. They occur in very young women (teenagers and women under 30 years of age) and persist undiscovered through the age at which the first mammogram is obtained, then, upon discovery, become a concern of both physician and patient. They may also become palpable or mammo-graphically visible in older women after previously normal mammograms. They continue to be a management problem, because fibroadenoma and carcinoma have overlapping mammographic features and both are common lesions in middle-aged women. With age, fibroadenomas become invo-luted and heavily calcified, thereby revealing their true iden-tity (Figure 5-21). Without this appearance, however, biopsy is often necessary.

A high index of suspicion and careful evaluation, together with either close follow-up or liberal use of needle biopsy, are needed to minimize both false-negative impressions and ex-cessive breast surgery.