Breast Pathology

Question 1

Breast Embryology

Answer 1

Modified sweat gland, Derived from skin

Breast tissue (and pathology) anywhere along milk line, axilla to vulva

Question 2

Breast Anatomy & Physiology

Answer 2

Duct-lobular-unit is functional unit
~ Glands produce milk

Both are lined by two layers of epithelium:
-Luminal cell layer (Produce milk)
-Myoepithelial cell layer (Contractile)

Breast tissue is hormone sensitive (receptors for E & P)
-Develop after menarche, esp RUQ
-Tender during menstrual cycle
-Hyperplasia during pregnancy
-Atrophy after menopause

Question 3

Galactorrhea

Answer 3

Production of milk outside of lactation

Due to nipple stimulation, prolactinoma of anterior pituitary, or drugs

NOT a symptom of breast CA

Question 4

Acute Mastitis

Answer 4

Breast-feeding creates small fissures, entry-way for Staph aureus

Warm, erythematous with PURULENT nipple discharge

Continue drainage/ breast-feeding
DiCLOXicillin

Complications: Abscess

Question 5

Periductal Mastitis

Answer 5

Inflammation of subareolar ducts

Due to relative vitamin A deficiency (in smokers)
-SQ metaplasia of specialized epithelium of lactiferous ducts
-Duct plugged with keratin
-Duct inflamed

Subareolar mass with nipple retraction
-B/c heals with fibrosis
-B/c myofibroblasts contract, pull on skin

Question 6

Mammary Duct Ectasia

***Not every mass in post-menopausal F is breast CA

Answer 6

Ectasia = Dilation of tubular structure

Subareolar mass with “GREEN-BROWN” discharge

Biopsy shows chronic inflammation with plasma cells

MultiPAROUS POST-meno women

Question 7

Breast Fat Necrosis

Answer 7

Trauma related, patient may not recognize
Mass on exam OR calcification on MAM

Biopsy also shows GIANT CELLS

Question 8

Fibrocystic Change

Answer 8

Benign, Most common change PRE-meno

Fibrotic CT + Cystic lobules/ducts
+/- Apocrine metaplasia

?Due to changes in E & P over time

Presents as “lumpy” breast, especially RUQ
Cysts have “blue-domed” appearance

Question 9

Changes WITH Increased Risk for Invasive CA

Answer 9

Ductal hyperplasia (extra epithelium)
Lobular hyperplasia
Sclerosing adenosis (extra glands)

Question 10

Intraductal Papilloma VS. Papillary Carcinoma

Answer 10

Benign
Growth in duct, still lined by two-layer epithelium

Bloody nipple discharge because vascular
Pre-meno women

C/c Papillary Carcinoma:
-Post-meno women (Incidence increases with age)
-No myoepithelial cell layer

Question 11

Fibroadenoma VS. Phyllodes Tumor

Answer 11

-Benign, CT & glands
-Estrogen-sensitive***
-Marble-like, mobile mass
-Most common TUMOR pre-meno

-Benign/ malignant
-Fibroadenoma-LIKE tumor with leaf-like projections
-POST-meno women

Question 12

Breast Cancer

Answer 12

Risk related to estrogen exposure
-Female sex
-Older age
-Early menarche/ late menopause
-Obesity
-Atypical hyperplasia
-First-degree relative with breast CA

Question 13

Ductal Carcinoma In Situ
(DCIS)

VS.

Invasive Ductal Carcinoma (IDC)

Answer 13

Malignant proliferation of cells in duct

-NO MASS on exam
-Comedo-Type = High grade with necrosis and calcification on MAM (Central cells lose blood supply & die)

+/- Paget Disease of Nipple
-Erythema, ulceration
-Underlying CA

VS.

-WITH MASS, dimpled skin, nipple retraction
-Biopsy shows duct-like structures within desmoplastic stroma

Question 14

Invasive Ductal Carcioma Special Subtypes:

Tubular

Answer 14

Produce tubules WITHOUT contractile cell layer, within desmoplastic stroma

Good prognosis

Question 15

Invasive Ductal Carcioma Special Subtypes:

Mucinous

Answer 15

Malignant cells floating in mucus
Seen in elderly women
Good prognosis

Question 16

Invasive Ductal Carcioma Special Subtypes:

Inflammatory

Answer 16

Biopsy shows tumor in dermal lymphatics
POOR prognosis

Ddx: Acute Mastitis (NO RESPONSE TO ABX)

Question 17

Invasive Ductal Carcioma Special Subtypes:

Medullary

Answer 17

High grade malignancy
+Lymphocytes & plasma cells

Seen in BRCA1 mutation

Question 18

Lobular Carcinoma In Situ (LCIS)

VS.

Invasive Lobular Carcinoma (ILC)

Answer 18

Malignant proliferation of cells in LOBULES
Dyscohesive, lack E-cadherin (Do NOT form ducts)

-No mass, found incidentally
-Multifocal & bilateral
-Rx TamOXifen!

VS.

-Cells grow & invade in “single-file”

Question 19

Prognosis Based on TNM Staging

Answer 19

Metastasis - Most important factor, but not many patients present this way

Spread to axillary lymph node - Most useful factor in determining prognosis

Sentinel lymph node biopsy***

Question 20

Predictive Factors

Answer 20

Predict response to treatment
1. Estrogen receptor
2. Progesterone receptor
3. HER2/Neu gene amplification

If tumor expresses ER & PR
-Respond to anti-E agents (TamOXifen)

If tumor has HER2/Neu amplification
(Growth factor receptor)
-Respond to anti-growth ab’s (TrastuzUMAB)

If tumor negative for all three predictive markers
-“Triple-Negative”
-POOR prognosis

Question 21

Hereditary Breast Cancer

Answer 21

Multiple first-degree relatives with breast CA
Tumor at pre-meno age
Multiple tumors

Single Gene Mutations
-BRCA1: Breast & ovarian carcinoma
-BRCA2: Breast carcinoma in M

May opt for prophylactic mastectomy & breast reconstruction

Question 22

Male Breast Cancer

Answer 22

Rare subareolar mass under nipple
Older males
Nipple discharge

Usually develop IDC (Male breast is mostly DUCTS, less lobules)

Associated with BRCA2 mutation & Klinefelter syndrome (XXY)