Non-Malignant Breast Pathologies

[liveonearth]

NORMAL ANATOMY
--breasts are modified sweat glands
--glands supply 4-18 lactiferous ducts, each duct with separate opening at nipple
--also adipose, CT (collagen & elastin) & ligamentous tissue (Cooper's ligaments)
--ratio of gland to adipose is 1:1 in non-lactating, 2:1 or more when lactating
--ducts & lobules lined w/ luminal epithelial cells & myoepithelial cells
--luminal EC's of lobule and termical duct produce milk
--luminal EC's lining the large ducts do not produce milk
--myoepithelial cells eject milk and maintain structure/fx of lobule & basement memb
--Montgomery tubercles = glands on areola
--75% of lymph from breasts goes to axillary lymph nodes
--axillary nodes incl: pectoral, subscapular, humeral
--25% of lymph goes to parasternal, the other breast, or abdominal LN's

CHANGES WITH AGE:
--prepubertal breast: large duct system ends in terminal ducts, minimal lobule formation
--menarche: terminal ducts give rise to lobules, interlobular (fibrous) stroma increases in volume
--in 30's breast lobules and specialzed stroma normally begin to INVOLUTE
--after menopause: lobules disappear, interlobular stroma replaced w/ adipose, loose CT gains density
--adipose makes mammogram darker (radiolucent) making radiodense lesions, calcifications visible

CHANGES DURING MENSTRUAL CYCLE:
--estrogen stimulates duct elongation & branching, incr vol & elasticity of CT, incr deposition of fat, incr elasticity of ducts
--progesterone stimulates lobule formation
--days 3-7: est-->epithelial cell prolif
--days 8-14: est promotes differentiation of EC's
--days 15-20: prog-->incr size of acinii, lumen, ducts
--days 21-27: intralobular stromal edema and venous congestion (ouch!)
--days 27-30: drop in est & prog-->decrease in stromal edema and decrease in lumen size
--day 1 (menses onset): est & prog decr-->EC apoptosis, edema resorbed, lobules regress
--best time to examine: just after menses

CHANGES WITH PREGNANCY
--morphological maturation and functional activity
--at full term breast if mostly lobules w/ little stroma between
--Montgomery tubercles increase in number-->lubricate nipple
--milk produced in late preg and first 4-10 days after birth = colostrum
--colostrum changes to milk as prog levels drop
--milk will keep coming HOW LONG if nursing is continuous???
--HOW LONG does it take for a woman to stop producing if there is interruption in nursing???
--after cessation of lactation lobules involute and breast size diminishes

CONGENTIAL CONDITIONS OF THE BREAST
--amastia = no breast, nipple, areola
--amazia = nipple and areola present but no breast tissue
--athelia = has glandular tissue but not nipple or areola, assoc w/ pyrogyria (sp?) premature aging
--supernumerary nipples = extras, present in 2-6% of females and 1-3% of males (COMMON!), usu along milk line (like on cats) from axilla to groin
--supernumerary breasts = extras! dt embryonic development but becomes apparent in puberty or preg/lactation, usu along milk line, rarely beyond mammary line (where's that?)
--mammary line is same as midclavicular line

--inverted nipples = retracted usudt fibrous tissue anchor, sometimes protrudes w/ stim, usu not, present in 3% of women, 90% bilateral, 50% familial, usu can breastfeed, sometimes breastfeeding permanently corrects inversion, if your nipple was a stickie outie and then inverts GET IT CHECKED: DDX: ectasia,

GALACTORRHEA
--spontaneous milk flow w/o childbirth/nursing
--mbdt excessive stim
--more often dt hormone dysregulation or meds (prolactin)

MASTITIS
--inflam of the parenchyma
--usu in lactating mothers, "puerperal mastitis"
--if not in lactating mother: "nonpuerperal mastitis"
--inflamed area may have "pie" shape dt backed up duct
--most often sterile & noninfectious (??)
--when infectious, usually staph epidermis of strep epidermitis, see fever, LAD
--bact introduced via cracks/fissures in nipples
--Tx: warm compress

PERI-DUCTAL MASTITIS
--aka recurrent subareolar abscess or squamousmetaplasia of lactiferous ducts
--painful erythematous subareolar mass
--in men and women (preg not necc)
--over 90% of pts are smokers!
--common sequelae: nipple inversion
--risk: abscess
--MORPH: keratinizing squamous epithelium extends deeper into duct at nipple than it should
--dilation and rupture of duct occur-->chronic granulomatous inflam response
--predisposes you to MAMMARY DUCT ECTASIA

MAMMARY DUCT ECTASIA
--onset usu in 5-6th decade of life
--mc in multiparous women
--NOT assoc w/ smoking (??)
--S/Sx: thick-white secretions, palpable diffuse periareolar mass, usu not red or painful
--MORPH: dilated ducts fill w/ granular debris incl lipid laden macrophages
--peri-ductal and interductal inflam, infiltrates w/ lymphs, macrophages, plasma cells
--fibrosis may produce overlying skin and nipple retraction
--may be mistaken for cancer via palp or mammogram, shape is similar

FAT NECROSIS
--etio: usu trauma, surgery-->hemorrhage-->liquifactive necrosis of fat-->fibroblastic prolif & incr vasc
--MORPH: eventual calcification, hemosiderin deposition, replacement w/ scar tissue
--SX: painless mass, skin thickening or retraction, mammographic density of calcification
--mb confused with cancer as palpable mass or calcifications on mammogram
--dent in boob where seatbelt goes, after accident

LYMPHOCYTIC MASTOPATHY
--most common in women with type I diabetes or AI thyroiditis (Hashimotos)
--single or multiple hard plapable masses made of collagenized stroma surrounding atrophic ducts/lobules
--thickening of basement membrane
--lymphocytic infiltrate surrounds epithelium and BVs
--hypothesized that it mb autoimmune dz of breast

GRANULOMATOUS MASTITIS
--uncommon (less than 1% of breast Bx)
--caused by many conditions incl: sarcoidosis, Wegener's granulomatosis, mycobact, fungus esp in immunocompromised, nipple piercing and bresat prosthesis also in immunocompromised

FIBROCYSTIC BREAST DZ
--noncancerous lumps
--30-60% of women get them
--mb ASx or periodic discomfort w/ cycle
--Dx: clinical and Hx, still worried-->fine needle Bx, mammogram
--papillomatosis found on bx-->higher risk of malignancy
--Tx: lifestyle change or drain cysts w/ needle

ADENOMA
--increased number of glandular components
--as glandular tissue becomes more organized it gets this name ???
--benign

FIBROADENOMA
--most common benign tumor of breast
--well circumscribed mass w/ fibrotic capsule: encapsulated
--firm, moveable, mb tender
--hyperplasia of intraductal ECs
--NORMAL nuclei & ratio to cytoplasm
--pearly, smooth (removed)
--hormonally responsive, increase during preg and late luteal phase, regress after menopause
--minimally increased risk of carcinoma

LACTATING ADENOMA
--pituitary adenoma is mc pit tumor
--causes incr in prolactin-->lactation in males or females

INTRADUCTAL PAPILLOMA
--1-3% of all breast Bx specimens
--usu benign, potential for malig
--myoepithelial cells, fibroblasts
--mc cause of unilateral discharge