Download The Breast

The Breast
The Breast
Acute mastitis
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S. aureus
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Breastfeeding
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Fever, erythema, pain
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Strep infections tend to cause diffuse spreading infection of entire breast
Periductal mastitis
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AKA recurrent subareolar abscess, squamous metaplasia of lactiferous ducts, Zuska disease
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Painful erythematous subareolar mass
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smoking
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Keratinizing squamous metaplasia of nipple ducts
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Inverted nipple
Fibrocystic disease
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“LUMPY, BUMPY”
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Non proliferative
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dense with cysts (blue-dome cysts)
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“milk of calcium” (mammograph term to describe calcifications that line bottom of rounded cyst)
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Adenosis (increase in # of acini per lobule)
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lactational adenomas = palpable masses in pregnant or lactating women
Breast Cancer
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Carcinoma of the breast is the most common
non-skin cancer in women
If lives to age 90 years 1/8 chance
Main benefit of screening with mammograms is
the detection of small, predominantly ERpositive invasive carcinoma and insitu
carcinoma (DCIS)
The major risk factors are hormonal and genetic
Breast CA risk factors
Hormonal
 Postmenopausal hormone replacement therapy increases risk
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Progesterone addition increases further
Age at menarche/menopause
 Reproductive Hx, breastfeeding
Genetic
 BRCA1 associated breast CA
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BRCA2 associated breast CA
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Poorly differentiated
Medullary features
Triple negative phenotype (ER-, PR-, and HER2/neu-)
Poorly differentiated
More often ER+ than BRCA1
P53 (Li-Fraumeni)
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Most commonly mutated gene in sporadic breast CA
DCIS
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Most detected as calcifications on mammo
Limited to ducts and lobules by BM
Intraductal carcinoma
Divided into 5 architectural types:
1) Comedocarcinoma (pleomorphic cells; microinvasion most common)
2) Solid (monomorphic; fills spaces)
3) Cribiform (monomorphic; cookie-cutter)
4) Papillary (monomorphic; grows along cores no myoepithelial layer)
5) Micropapillary (monomorphic; no core)
Paget disease of nipple (erythema, crust, extend from DCIS; palpable
mass in most)
Invasive (Infiltrating) Carcinoma
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Palpable tumors are associated with axillary lymph node metastases
50% of the time
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**axillary lymph node status is the most important prognosis factor for invasive
carcinoma in the absence of distant metastases
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Dimpling of skin
Peau d’orange
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Inflammatory carcinoma
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Tumors presenting with swollen, erythematous breast
Extensive invasion and obstruction of dermal lymphatics by tumor cells
Many metastases at diagnosis
Rapid recurrence
Invasive carcinoma, NST
(invasive ductal carcinoma)
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Majority of carcinomas are NST
Firm to hard and have an irregular border
Grate sound when cut
Streaks of chalky-white elastotic stroma
Desmoplasia
5 major patterns of gene expression:
1) Luminal A
2) Luminal B
3) Normal breast-like
4) Basal-like
5) HER2 positive
ER+, HER2/neu –
Triple+
ER+, HER2/neu –
Triple –, BRCA1
ER –
largest group, well differentiated, postmenopausal
high proliferation rate, lymph node metastases
like metaplastic carcinoma, high grade/metastases
Invasive Lobular Carcinoma
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Usually present as palpable mass
25% have little desmoplasia  rarely palpable
Greater incidence of B/L
Dyscohesive infiltrating tumor cells, no tubules
Signet-ring cells
Resembles signet-ring gastric carcinoma (loss of Ecadherin)
Metastases to peritoneum, retroperitoneum,
leptomeninges, GI tract, uterus, ovaries
Other carcinomas
Medullary
 6th decade
 Well-circumscribed
 Rapid growing
 Soft, fleshy
 Overexpression of adhesion
molecules:
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Pushing borders
Syncytial growth pattern
Lymph node metastases rare
Overexpression of adhesion
molecules
BRCA1 promoter
hypermethylation
Mucinous (colloid)
 Median age = 71
 Slow growing over many years
 Soft, rubbery
 Pale blue gelatin
 Pushing or circumscribed borders
Tubular (cribiform)
 Detected as small irregular
mammographic densities
 Late 40s
 Well-formed tubules
 Myoepithelial layer absent
 Apocrine snouts
 LCIS or lobular carcinoma
associated
 Excellent prognosis
More carcinomas
Invasive papillary
ER +
good prognosis
Invasive micropapillary
ER –
HER2 +
poor prognosis
Metaplastic carcinoma
 prominent spindle
 triple negative
 Poor prognosis
Stromal Tumors
Fibroadenoma
 most common benign tumor of female (20s and 30s)
 Multiple, B/L
 sharply circumscribed, freely mobile
 From intralobular stroma
 popcorn calcifications
 post renal transplant treated w/ cyclosporin A
Phyllodes tumor
 6th decade
 Leaflike
 From intralobular stroma
 EGFR amplification
Stromal tumors
Interlobular stromal tumors (benign)
Pseudoangiomatous stromal hyperplasia
Myofibroblastoma
Lipomas & hamartomas
Fibromatosis
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Locally aggressive but doesn’t metastiasize
Mostly sporadic
Some associated with familal adenomatous polyposis and Gardner syndrome
B-catenin in nucleus is useful diagnostic feature
Angiosarcoma (malignant)
malignant post radiation therapy
Young women
Stewart treves syndrome – angiosarcoma from edematous extremity after
mastectomy
Male Breast
Gynecomastia
 puberty, elderly, cirrhosis, Klinefelter, steroids
Carcinoma
 Klinefelter
 BRCA2
 Usually present as palpable subareolar mass
 Nipple discharge common symptom
 Distant metastases to lungs, brain, bone, liver common