Chapter 16 Flashcards
Describe breast tissue
Modified sweat gland embryologically derived from the skin (breast tissue can develop anywhere along the milk line, when runs from the axilla to the vulva (e.g. supernumerary nipples)
The ______ is the functional unit of the breast
Terminal duct lobular unit- lobules make milk that drains via ducts to the nipple
Lobules and ducts are lined by two layers of epithelium. Explain
Luminal cell layer- inner cell layer lining the ducta and lobules- responsible for milk production in the lobules
Myoepithelial cell layer- outer cell layer lining duct and lobules; contractile function propels milk towards the nipple
Breast tissue is hormone sensitive. How?
Before puberty, male and female breat tissue primarily consist of large ducts under the nipple.
Development after mecnarche is primarily driven by estogrne and progesterone; lobules and small ducts form and are present in highest density in the upper outer quadrant
During pregnancy, breast lobues undergo hyperplasia, driven by estrogen and progresterone produced by the corpus luteum (early first trimester), fetus, and placenta (later in pregnancy)
What is galactorrhea?
Milk production outside of lactation (not a symptom of breast cancer and most commonly due to excessive prolactin production)
What is this?
Acute mastitis- bacterial infeciton of the breast, usually due to S. aureus associated with breast-feeding (erythmatous breast and may see purulent nipple discharge)
Usually from the child- no need to stop breast-feeding
How is acute mastitis tx?
Drainage and ABX (e.g. dicloxacillin)
What is periductal mastitis?
Inflammation of the subareolar ducts usually seen in smokers
Relative vitA deficiency results in squamous metaplasia of the latiferous ducts, producing duct blockage and inflammation (clinically presents as a subareolar mass with nipple retraction)
Describe mammary duct ectasia
Inflammation with dilation (ectasia) of the subareolar ducts (rare and classically presents in multiparous postmenopausal women)
Look for discharge
When is fat necrosis of the breast most common?
Usually related to trauma, however a Hx of trauma may not always be evident
Presents as a mass on physical exam or abnormal calcification on mammography due to saponification
What are some common benign tumors and fibrocystic changes of the breast?
Fibrocystic change
Intraductal papilloma
Fibroadenoma
Phyllodes Tumor
Describe Fibrocystic change
Development of fibrosis and cysts in the breast (most common change in the premenopausal breast and hormone mediated)
Presents with a breast lump; usually in the upper outer quadrant
Can have a blue-dome appearance
Fibrocystic changes are benign, BUT some fibrocystic-related changes are associated with an increased risk for invasive carcinoma, namely:
Fibrosis, cyssts, and apocrine metaplasia- no increased risk
Ductal hyperplasia and sclerosing adenosis- 2x risk
Atypical hyperplasia- 5x risk
What is an intraductal papilloma?
Papillary growth, usually into a large duct marked by fibrovascular projections lined by epithelial (luminal ) and myoepithelial cells
How does intraductal papilloma classically present?
Bllody nipple discahrge in premenopausal women (must be distinguished from papillary carcinoma, which also presents as blood nipple discharge, but it mared by fibrovascular projections lined by epithelial cells WITHOUT underlying myoepithelial cells)
Describe fibroadenomas of the breast
Tumor of fibrous tissue and glands (most common benign neoplasm of the breast; usually seen in premenopausal women)
Presents as a well-circumscriebed, mobile marble-like mass
Estrogen sensitive- grows during preganncy and may eb painful during the menstrual cycle
No risk of carcinoma
Describe phyllodes tumors
Fibroadenoma like tumor with overgrowth of the fibrous compoenent with classic ‘leaf-like’ projections on biopsy
Can be malignant
What is a ductal carcinoma in situ?
Malignant proliferation of cells in ducts with no invasion of the basement membrane often detected as calcification on mammography- DCIS does not usually produce a mass)
What is Paget disease of the breast?
DCIS that extends up the ducts to involve the skin of the nipple and presents as nipple ulceration and erythema
Describe tubular IDC
Marked well-differentiated tubules that lack myoepithelial cells (good prognosis)
Describe mucinous IDC
Marked by carcinoma with abundant extracellular mucin (tumor cells floating in a mucus pool)
Tends to occur in women 70+ yo
good prognosis
Describe medullary IDC
marked by large, high-grade cells growing in sheets with associated lymphocytes and plasma cells
grows as a well-circumscribed mass that can mimic fibroadenoma on mammography
Good prognosis
Increased incidence in BRCA1 carriers
What is this showing?
Invasive lobular carcinoma with the classic ‘indian file’ due to loss of E-cadherin
