Pathology of Breast I - Breast Disorders

Question 1

Mammary Duct Ectasia

Answer 1

*Benign inflammatory condition

*Affects older women (~50 years old)

*Classically in
multiparous women

*Distension (ectasia) of subareolar ducts (nipple)

*Due to chronic inflammation and fibrosis

*Presents as breast mass with thick, white discharge

*Usually no pain, erythema

*Must be differentiated from breast cancer

Question 2

Mammary Duct Ectasia histology

Answer 2

Periductal inflammation and dilation of ducts, with foamy histiocytes within the luminal secretions and infiltrating the wall of ducts

Question 3

Fat necrosis

Answer 3

results from trauma (sports or seatbelt)

Benign, inflammatory process

Often mimics breast cancer

Biopsy shows fat necrosis with inflammatory cells

Question 4

Lactational (acute) Mastitis

Answer 4

Occurs in women during breast feeding

Trauma to skin around nipple

Breast erythema, tenderness

Often fever, malaise

Most commonly infection with S. Aureus

Usual treatment: dicloxacillin or cephalexin

Mother should continue nursing

Can progress to abscess requiring drainage

Question 5

Periductal Mastitis (Squamous Metaplasia of Lactiferous Ducts)

Answer 5

Inflammation of subareolar ducts

More than 90% cases occur in female smokers

Cells produce keratin and block the duct resulting inflammation

Periareolar mass with redness, tenderness, warmth

Often 2° infection requiring antibiotics

Often requires incision/drainage

Question 6

Fibrocystic Changes

Answer 6

Group of breast changes/lesions
All are benign

Non-proliferative

Not associated with risk of cancer

Occur in ages 25-45 years

Must be distinguished from breast cancer

Question 7

Fibrocystic Changes

Answer 7

simple
fibrosis
apocrine metaplasia

Question 8

simple cyst

Answer 8

Occur in terminal duct lobular unit

Fluid-filled, round cysts

Filled with dark fluid

Cyst looks blue dome on gross exam

Question 9

• Fibrosis

Answer 9

Cyst rupture  inflammation  fibrosis

Question 10

Apocrine metaplasia

Answer 10

Also called “benign epithelial alteration”

Alterations to lobular epithelial cells

Take on the appearance of apocrine (gland) cells

Question 11

Proliferative Breast Disorders

Answer 11

• Proliferation of epithelial cells
• Benign
• No atypia
• Small increase in risk of breast cancer

Question 12

key types of proliferative breast disorders

Answer 12

• Epithelial hyperplasia
• Sclerosing adenosis
• Intraductal papilloma

Question 13

Proliferative Breast Disorders- Epithelial Hyperplasia

Answer 13

• Normal ducts/lobules: double-layer epithelium
• Luminal cells and myoepithelial cells
• Epithelial Hyperplasia: ↑ luminal/myoepithelial cells
• Distended ducts or lobules
• Lumen filled with cluster of cells

Question 14

Proliferative Breast Disorders- Sclerosing Adenosis

Answer 14

• Increased number of compressed acini
• Dense stroma
• May result in calcifications
• Slightly increased risk for invasive carcinoma

Question 15

Proliferative Breast Disorders- Intraductal Papilloma

Answer 15

• Benign breast lesion
• Abnormal proliferation of the epithelial cells lining the breast ducts
• Cells grown in “finger-like” projections

Question 16

What are the clinical findings of Proliferative Breast Disorders- Intraductal Papilloma

Answer 16

• Ages 35 to 55
• Present with bloody/serous discharge
• May also have a small mass near the nipple
• Cells grown in “finger-like” projections

Question 17

stromal tumors

Answer 17

• Neoplastic epithelial/mesenchymal lesions
• Stromal growth may trigger epithelial proliferation
• Both arise from intralobular stroma

Question 18

2 types of stromal tumors

Answer 18

• Fibroadenoma
• Phyllodes Tumor

Question 19

Fibroadenoma

Answer 19

• Most common benign breast tumor
• Masses of fibrous and glandular tissue
• Compressed epithelial lined spaces
• Hypoechoic on ultrasound

Question 20

Clinical/histo of fibroadenoma

Answer 20

• Occurs ages 15 to 35 years
• Hormone sensitive
• Increase in size during menstrual cycle/pregnancy
• Decrease in size after menopause
• Well-defined, solid, mobile mass
• Develop lobules
• Not usually require treatment
• Can be removed surgically

Question 21

types of fibroadenoma

Answer 21

Juvenile fibroadenoma
Complex
Simple

Question 22

Phyllodes Tumor

Answer 22

Benign stromal fibroepithelial tumor

Question 23

stromal fibroepithelial tumor

Answer 23

• Benign (usually), borderline, malignant
• Both epithelial and stomal tissue grow rapidly
• Low-grade forms similar to fibroadenomas
• High-grade variants can metastasize