The BreastThe Breast

The BreastThe Breast

Acute mastitisAcute mastitis

S. aureusS. aureus

BreastfeedingBreastfeeding

Fever, erythema, painFever, erythema, pain

Periductal mastitis – Periductal mastitis – subareolar mass, subareolar mass, smoking, keratinizingsmoking, keratinizing

Fibrocystic diseaseFibrocystic disease

““LUMPY, BUMPY”LUMPY, BUMPY”

dense with cystsdense with cysts

nonproliferativenonproliferative

Breast CancerBreast Cancer

Carcinoma of the breast is the most Carcinoma of the breast is the most common non-skin cancer in womencommon non-skin cancer in women

If lives to age 90 years 1/8 chanceIf lives to age 90 years 1/8 chanceMain benefit of screening with Main benefit of screening with

mammograms is the detection of small, mammograms is the detection of small, predominantly ER-positive invasive predominantly ER-positive invasive carcinoma and insitu carcinoma (DCIS)carcinoma and insitu carcinoma (DCIS)

The major risk factors are hormonal and The major risk factors are hormonal and geneticgenetic

DCIS DCIS (calcifications on mammo)(calcifications on mammo)Comedocarcinoma Comedocarcinoma (pleomorphic cells; (pleomorphic cells;

microinvasion most common)microinvasion most common)

Solid Solid (monomorphic; fills spaces)(monomorphic; fills spaces)

CribiformCribiform (monomorphic; cookie-cutter) (monomorphic; cookie-cutter)

Papillary Papillary (monomorphic; grows along cores no (monomorphic; grows along cores no myoepithelial layer)myoepithelial layer)

Micropapillary (Micropapillary (monomorphic; no core)monomorphic; no core)

Paget disease Paget disease (erythema, crust, extend from (erythema, crust, extend from DCIS; palpable mass in most)DCIS; palpable mass in most)

Invasive (Infiltrating) CarcinomaInvasive (Infiltrating) Carcinoma

Palpable tumors are associated with axillary lymph node metastases Palpable tumors are associated with axillary lymph node metastases 50% of the time – Axillary lymph node status is the most important 50% of the time – Axillary lymph node status is the most important prognosisfactor for invasive carcinom in the absence of distant prognosisfactor for invasive carcinom in the absence of distant metastases metastases

Peau d’orangePeau d’orangeInflammatory carcinomaInflammatory carcinoma

NST NST (invasive ductal)(invasive ductal) – luminal A – luminal A (ER+, HER2/neu -)(ER+, HER2/neu -), Luminal B , Luminal B (triple (triple positive)positive), normal breast-like, normal breast-like (ER+, HER2/neu-) (ER+, HER2/neu-), basal-like , basal-like (triple (triple negative; BRCA1),negative; BRCA1), HER2 positive; HER2 positive; grating sound when cutgrating sound when cut

Lobular Lobular Tubular/cribiformTubular/cribiformMucinous/colloidMucinous/colloidMedullaryMedullaryPapillaryPapillaryMetaplastic Metaplastic

NSTNST

Luminal A – ER+, HER2/neu –Luminal A – ER+, HER2/neu –

Luminal B – Triple-positiveLuminal B – Triple-positive

Normal breast-like – ER+, HER2/neu –Normal breast-like – ER+, HER2/neu –

Basal-like – triple negative, BRCA1 Basal-like – triple negative, BRCA1 (similar (similar to metaplastic carcinoma)to metaplastic carcinoma)

HER2 positive – ER-HER2 positive – ER-

Grate sound when cutGrate sound when cut

DesmoplasiaDesmoplasia

Invasive Lobular CarcinomaInvasive Lobular Carcinoma

Little desmoplasia, Little desmoplasia, rarely palpablerarely palpable

Dyscohesive infiltrating tumor cells, no Dyscohesive infiltrating tumor cells, no tubulestubules

Resembles signet-ring gastric carcinoma; Resembles signet-ring gastric carcinoma; loss of E-cadherinloss of E-cadherin

Metastases to peritoneum, Metastases to peritoneum, retroperitoneum,leptomeninges, GI tract, retroperitoneum,leptomeninges, GI tract, uterus, ovariesuterus, ovaries

MedullaryMedullary

Well-circumscribedWell-circumscribed

Soft, fleshySoft, fleshy

Lymph node Lymph node metastases are raremetastases are rare

overexpression of overexpression of adhesion moleculesadhesion molecules

BRCA1 promoter BRCA1 promoter overexrpession; overexrpession; pushing borderspushing borders

MucinousMucinous

Soft, rubberySoft, rubbery

Pale blue gelatinPale blue gelatin

pushing or circumscribed pushing or circumscribed bordersborders

Tubular Tubular

Well-formed tubulesWell-formed tubules

small; myoepithelial layer small; myoepithelial layer absent; LCIS or lobular absent; LCIS or lobular carcinoma associatedcarcinoma associated

Invasive papillary – Invasive papillary – ER positive good ER positive good prognosisprognosis

Invasive Invasive micropapillary – ER micropapillary – ER negative, HER2 negative, HER2 positive poor positive poor prognosisprognosis

Metaplastic Metaplastic carcinoma – carcinoma – prominent spindle, prominent spindle, triple negativetriple negative

Stromal Tumors Stromal Tumors

Fibroadenoma – most common benign tumor, sharply circumscribed, Fibroadenoma – most common benign tumor, sharply circumscribed, freely mobile freely mobile (intralobular stroma; popcorn calcifications; post renal (intralobular stroma; popcorn calcifications; post renal transplant treated with cyclosporin A)transplant treated with cyclosporin A)

Phyllodes tumor- leaflike Phyllodes tumor- leaflike (intralobular stroma; EGFR amplification)(intralobular stroma; EGFR amplification)

Interlobular stromal tumors – Interlobular stromal tumors – pseudoangiomatous stromal hyperplasia, pseudoangiomatous stromal hyperplasia, myofibroblastoma, lipoma, hamartomas, fibromatosis (gradner myofibroblastoma, lipoma, hamartomas, fibromatosis (gradner syndrome; B-catenin)syndrome; B-catenin)

Angiosarcoma – malignant post radiation therapy; Stewart treves Angiosarcoma – malignant post radiation therapy; Stewart treves syndrome (angiosarcoma from edematous extremity after syndrome (angiosarcoma from edematous extremity after mastectomy)mastectomy)

Male BreastMale Breast

Gynecomastia Gynecomastia (puberty, elderly, cirrhosis, (puberty, elderly, cirrhosis, Klinefelter, steroids)Klinefelter, steroids)

CarcinomaCarcinoma

KlinefelterKlinefelter

BRCA2BRCA2