3. Benign epithelial conditions

Question 1

Types of benign epithelial conditions

Answer 1

1. Non-proliferative breast changes
2. Proliferative breast disease without atypia
3. Proliferative breast disease with atypia

Question 2

Definition of non-proliferative breast changes

Answer 2

Also known as fibrocystic changes of the breast; includes a number of very common morphologic alterations to the breast which are non-proliferative in nature

Question 3

Epidemiology of non-proliferative breast changes

Answer 3

1. Produces symptoms in at least 10% of women

2. Occurs during reproduction decades, with peak incidence in the premenopausal decade

Question 4

Types of alterations in non-proliferative breast changes

Answer 4

1. Cysts & apocrine metaplasia
   - Unopened cysts containing turbid blue fluid (hence also called blue-domed cysts)
   - Cysts lined by flattened atrophic epithelium or by metaplastic apocrine cells
   - Apocrine cells have abundant eosinophilic cytoplasm & round nuclei
2. Fibrosis
   - Due to chronic inflammatory reaction to contents of cysts released when cysts rupture
3. Adenosis
   - Increase in the number of acini per lobule

Question 5

Clinical features of non-proliferative breast changes

Answer 5

1. Presents as a lump or lumpiness

2. No increased risk of invasive breast carcinoma

Question 6

Definition of proliferative breast disease without atypia

Answer 6

Lesions characterized by proliferation of ductal epithelium &/or stroma w/o cytologic or architectural features suggestive of carcinoma-in-situ

Question 7

Types of lesions under proliferative breast disease without atypia

Answer 7

1. Epithelial hyperplasia
   - Presence of >2 cell layers in epithelial lining of ducts
2. Sclerosing adenosis
   - Number of acini per terminal duct is at least twice that of uninvolved lobules
   - Dense stromal fibrosis
3. Large duct papillomas
   - Papillomas are exophytic growths with fibrovascular cores lined by luminal & myoepithelial cells
   - Grow within the lumen of lactiferous ducts (hence may present with bloody nipple discharge)

Question 8

Clinical features of proliferative breast disease without atypia

Answer 8

Slightly increased risk (1.5-2x) of invasive breast carcinoma

Question 9

Types of lesions under proliferative breast disease with atypia

Answer 9

1. Atypical ductal hyperplasia
   - Histologic resemblance to ductal carcinoma-in-situ except that it is limited & only partially fills ducts
2. Atypical lobular hyperplasia
   - Histologic resemblance to lobular carcinoma-in-situ except that cells do not fill or distend more than 50% of acini within a lobule

Question 10

Clinical features of proliferative breast disease with atypia

Answer 10

Significantly increased risk (5x) of invasive breast carcinoma