Pathology of Precursor Breast Lesions Flashcards
What is the breast?
- a modified sweat gland embryologically derived from the skin.
Where can breast tissue develop?
- anywhere along the MILK LINE, from the axilla to the vulva.
- more common on the left side.
What is the functional unit of the breast?
- terminal duct lobules
*** What lines the lobules and ducts of the breast?
- 2 layers of epithelium:
1. LUMINAL layer= inner layer lining the ducts and lobules responsible for milk production.
2. MYOEPITHELIAL layer= outer layer lining ducts and lobules; contractile function that propels milk towards the nipple.
What hormone receptors does breast tissue contain?
- progesterone receptors
2. estrogen receptors
** Where is the highest density of breast tissue in females after menarche?
- UPPER OUTER QUADRANT
Is breast tenderness a common complaint prior to menstruation?
YES
What happens to breast lobules during pregnancy?
- undergo 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?
- ATROPHY
What is GALACTORRHEA?
- milk production outside of lactation caused by nipple stimulation (physiologic), prolactinoma of the anterior pituitary (common pathologic cause) and drugs.
*** Is the abnormal production of milk (galactorrhea) a symptom of breast cancer?
NO
***What is acute mastitis?
- bacterial infection of the breast, usually due to Staph aureus that presents as a warm erythematous breast with purulent nipple discharge (may progress to abscess).
- associated with BREAST-FEEDING causing FISSURES/CRACKS in the nipple and entry for microbes.
How do you treat acute mastitis?
- drainage (e.g. feeding) and antibiotics (dicloxacillin).
*** What is periductal mastitis?
- inflammation of the SUBAREOLAR DUCTS (usually seen in smokers).
- presents as a mass with nipple retraction.
** What causes periductal mastitis?
- relative VITAMIN A deficiency (caused from smoking), which results in SQUAMOUS METAPLASIA of lactiferous ducts (normal columnar epithelium), producing duct blockage and inflammation.
** What is mammary duct ectasia?
- inflammation with DILATION (ECTASIA) of the wall of the SUBAREOLAR DUCTS.
- presents as a periareolar mass with GREEN-BROWN nipple DISCHARGE in MULTIPARoUS POSTmenopausal women.
What would a biopsy of mammary duct ectasia show?
- chronic inflammation with PLASMA cells.
*** What causes breast fat necrosis?
- usually related to TRAUMA, however a history of trauma may not always be evident.
- presents as a mass or abnormal CALCIFICATION on mammography (due to saponification).
What would a biopsy show on breast fat necrosis?
- necrotic fat with associated calcifications and GIANT cells.
** What is FIBROCYSTIC CHANGE of breast tissue?
- BENIGN development of FIBROSIS and CYSTS in the breast.
- presents as vague irregularity of the breast tissue (LUMPY BREAST), usually in the upper outer quadrant.
- most common change in PREmenopausal breast (thought to be hormone mediated). Oral contraceptives help by balancing hormones.
How do the cysts of fibrocystic breast change look on gross exam?
- BLUE-DOME appearance with histological eosinophilic cytoplasm.
*** Are some fibrocystic-related changes associated with an increased risk for invasive carcinoma?
YES (increased risk applies to BOTH BREASTS).
** If a woman has fibrosis, cysts, and apocrine metaplasia, is she at an increased risk for invasive carcinoma?
- NO
* this is unusual bc normally metaplasia increases your risk.
** If a woman has DUCTAL HYPERPLASIA or SCLEROSING ADENOSIS (both types of fibrocystic changes), is she at an increased risk for invasive carcinoma?
YES (2x increased risk).
*sclerosing adenosis is often calcified!
** Does ATYPICAL HYPERPLASIA increase a woman’s risk for invasive carcinoma?
YES (5x increased risk).
*look for ROMAN BRIDGES on histology.
*** What is INTRADUCTAL PAPILLOMA?
- papillary growth (usually into a LARGE DUCT) that is characterized by fibrovascular projections lined by epithelial and MYOEPITHELIAL cells in a PREmenopausal woman.
- presents as BLOODY NIPPLE DISCHARGE.
*** How do you distinguish intraductal papilloma from papillary carcinoma of the breast?
- papillary carcinoma has fibrovascular projections lined by epithelial cells WITHOUT underlying MYOepithelial cells, and is more commonly seen in a POSTmenopausal woman.
** What is a fibroadenOMA? (stromal tumor)
- MOST COMMON BENIGN tumor of fibrous tissue and glands that is ESTROGEN sensitive (painful during menstrual cycle).
- presents as WELL-CIRCUMSCRIBED, MOBILE marble-like mass is PREmenopausal women.
- histology may show STAGHORN configuration.
** What is a PHYLLODES tumor? (stromal tumor)
- fibroadenoma-like tumor with OVERGROWTH of the FIBROUS component; characteristic “LEAF-LIKE” projections seen on biopsy of a POSTmenopausal woman.
** Can PHYLLODES tumor be malignant in some cases?
YES
What is thelarche?
- rapid growth of breasts at onset of puberty (age 10-11 in females).
- influenced by estrogens, growth hormone and prolactin, but NOT progesterone.
How many lobes make up the breast?
15-25 lobe, emptying into separate major duct terminating in the nipple.
Into what is the breast lobule divided?
10-100 alveoli
What is macromastia?
- female breasts undergo rapid and massive enlargement at puberty
How do benign and malignant lesions tend to differ on mammography?
- benign= well-circumscribed and round.
- malignant= stellate and circular w or w/o calcifications
What is gynecomastia?
- enlargement of male breast tissue (specifically ducts without lobules) due to imbalance of estrogens and androgens.
- puberty related or associated with Klinefelter syndrome, marijuana, anabolic steroids, or psychoactive drugs.
- usually resolves spontaneously.
