Benign Epithelial Lesions of the Breast Flashcards
What is the association with benign histologic changes?
- Later development of invasive cancer
How can risk be reduced in benign epithelial lesions?
- Bilateral prophylactic mastectomy or treatment with estrogen antagonists (tamoxifen)
How many women with atypical hyperplasia have breast cancer? What do they ultimately decide to do?
- Around 20%
- Many choose to have close clinical and radiologic surveillance over intervention
What is the relative risk for nonproliferative breast changes turning into invasive carcinoma?
- 1 (~3%)
What is the relative risk for proliferative disease without atypia turning into invasive carcinoma?
- 1.5-2 (~5%-7%)
What is the relative risk for proliferative disease with atypia turning into invasive carcinoma?
- 4-5 (~13%-17%)
What is the relative risk for carcinoma in situ turning into invasive carcinoma?
- 8-10 (~25%-30%)
What is nonproliferative breast changes (fibrocystic changes)?
- Common morphologic alterations that are often grouped under the term fibrocystic changes
- “Lumpy bumpy” breasts on palpation
- Not associated with an increased risk of breast cancer
What are the three principal nonproliferative morphologic changes in nonproliferative breast changes?
- Cystic change, often with apocrine metaplasia
- Fibrosis
- Adenosis
What is adenosis?
- Increase in the number of acini per lobule
Where else is adenosis seen?
- Pregnancy
How do lactational adenomas present in pregnancy?
- Palpable masses in pregnant or lactating women and regress after cessation of breastfeeding
What does adenosis look like in nonpregnant women?
- Can occur as a focal change
- Acini are lined by columnar epithelial cells, and calcifications are occasionally present within the lumens
How is proliferative breast disease without atypia detected?
- Mammographic densities, calcifications, or incidental findings in biopsies performed for other reasons
How are the lesions in proliferative breast disease without atypia characterized by?
- Proliferation of epithelial cells, without cytologic atypia, and are associated with a small increase in the risk of subsequent carcinoma in either breast
- Lesions are considered predictors of risk, rather than direct precursors, of carcinomas
What are the morphologic features of proliferative breast disease without atypia?
- Epithelial hyperplasia
- Sclerosing adenosis
- Complex sclerosing lesion
- Papilloma
- Gynecomastia
What is sclerosing adenosis?
- The involved terminal duct lobular unit is enlarged, and the acini are compressed and distorted by dense stroma
- Calcifications are present within some of the lumens
How does sclerosing adenosis differ from carcinomas?
- In sclerosing adenosis, the acini are arranged in a swirling pattern, and the outer border is well circumscribed
What is seen in ~80% of large duct papillomas?
- Nipple discharge
What causes a bloody nipple discharge in large duct papillomas?
- Stalk undergoes torsion causing infarction
What causes a serous discharge in large duct papillomas?
- Intermittent blockage and release of normal breast secretions or irritation of the duct by the papilloma
How do most small duct papillomas come to clinical attention?
- As small palpable masses or as densities or calcifications seen on mammograms
How is proliferative breast disease with atypia detected?
- Mammographic calcifications or as incidental findings in biopsies performed for other reasons
How are the lesions in proliferative breast disease with aytpia characterized?
- By proliferations of either ductal or lobular epithelial cells, with some but not all of the histologic features of carcinoma in situ
- Associated with a moderate increase in the risk of subsequent carcinoma in either breast
What are the two morphologic features of proliferative breast disease with atypia?
- Atypical ductal hyperplasia (ADH)
2. Atypical lobular hyperplasia (ALH)
What does ADH and ALH express?
- High levels of estrogen receptor
- Have a low rate of proliferation
What chromosomal aberrations are seen in ADH and ALH?
- Losses of 16q and 17p or gains of 1q, which are features also found in low-grade carcinoma in situ and ER-positive invasive breast cancer
What is something that only ALH expresses?
- Loss of E-cadherin expression (shares this with LCIS)
What is the family of lobular neoplasia characterized by?
- Loss of cell adhesion
