Flashcards in CH16 - Breast Pathology Deck (118)
What is the breast?
modified sweat gland; embryologically derived from the skin
From where can breast tissue develop?
anywhere along the milk line, which runs from the axilla to the vulva (e.g., supernumerary nipples).
What is the functional unit of the breast?
the terminal duct lobular unit
What do the lobules make?
milk that drains via ducts to the nipple
What are the lobules and ducts lined by?
two layers of epithelium, luminal cell layer and myoepithelial layer
What is the luminal cell layer? Its function?
inner cell layer lining the ducts and lobules; responsible for milk production in the lobules
What is the myoepithelial cell layer? Its function?
outer cell layer lining ducts and lobules; contractile function propels milk towards the nipple.
What is the breast tissue sensitive to?
What does the male and female breast tissue primarily consist of before puberty?
large ducts under the nipple
What is the development after menarche primarily driven by?
estrogen and progesterone; lobules and small ducts form and are present in highest density in the upper outer quadrant.
What happens to the breast during the menstrual cycle?
Breast tenderness during the menstrual cycle is a common complaint, especially prior to menstruation.
What happens to the breast during pregnancy?
breast lobules undergo hyperplasia.
What is hyperplasia driven by?
estrogen and progesterone produced by the corpus luteum (early first trimester), fetus, and placenta (later in pregnancy)
What happens to breast tissue after menopause?
breast tissue undergoes atrophy.
What does galactorrhea refer to?
milk production outside of lactation.
Is galactorrhea related to breast cancer?
It is not a symptom of breast cancer.
What causes galactorrhea?
include nipple stimulation (common physiologic cause), prolactinoma of the anterior pituitary (common pathologic cause), and drugs.
What are the inflammatory conditions of the breast?
Acute mastitis, periductal mastitis, mammary duct ectasia, fat necrosis,
What is acute mastitis?
Bacterial infection of the breast, usually due to Staphylococcus aureus
What is acute mastitis associated with?
breast-feeding; fissures develop in the nipple providing a route of entry for microbes.
What does acute mastitis present as?
an erythematous breast with purulent nipple discharge; may progress to abscess formation
What does the treatment of acute mastitis involve?
continued drainage (e.g., feeding) and antibiotics (e.g., dicloxacillin).
What is periductal mastitis?
Inflammation of the subareolar ducts
What is periductal mastitis usually seen in?
In periductal mastitis, relative vitamin A deficiency results in what?
squamous metaplasia of lactiferous ducts, producing duct blockage and inflammation
How does periductal mastitis clinically present?
as a subareolar mass with nipple retraction
What is mammary duct ectasia?
Inflammation with dilation (ectasia) of the subareolar ducts
What is the frequency of mammary duct ectasia?
In whom does mammary duct ectasia classically arise?
in muciparous postmenopausal women