Breast Disorders B&B

Question 1

what are the anatomical parts of the terminal duct lobular units of the breast?

Answer 1

functional unit of the breast

milk is secreted from clusters of acini (sacs) within each lobule

milk travels through intralobular terminal ducts, which converge into an extralobular terminal duct

Question 2

what are the layers of the breast epithelium?

Answer 2

two layers rather than 1:

1. luminal epithelial cells: secrete milk
2. myoepithelial cells: contractile in response to oxytocin

Question 3

breast tissue develops from embryonic structures called ______

Answer 3

milk lines: 2 thickenings of ectoderm that form breast/nipples

form mammary ridges from axilla to groin, but disappear later except for the breast - extra nipples may form along these lines

Question 4

what is the effect of estrogen, progesterone, and prolactin on breast tissue?

Answer 4

estrogen: acts on ducts, causes increase in breast size during puberty, menstrual cycle (cyclic - tenderness), and pregnancy

progesterone: acts on lobules, causing growth in preparation for pregnancy/delivery

prolactin: increases breast size during pregnancy, inhibits ovulation during time when mother is still breastfeeding (lactating)

Question 5

what prevents milk formation by the breasts during pregnancy?

Answer 5

milk production before the baby is born would be a waste in nutrients and is inhibited by progesterone and estrogens

these hormones fall during delivery, allowing milk production to occur

Question 6

what hormones are required for maintenance of lactation?

Answer 6

“use it or lose it” - maintenance of lactation requires nipple stimulation and removal of milk, which triggers prolactin (anterior pituitary) and oxytocin (posterior pituitary) for continued milk production

absence of milk removal causes involution - if there is a break from breast feeding, the mother will not be able to do it again for that pregnancy

Question 7

explain why breastfeeding can decreases a mother’s risk of breast and ovarian cancer

Answer 7

prolactin inhibits ovulation during lactation (so mother cannot become pregnant while still breastfeeding)

more ovulation = more risk of breast/ovarian cancer, so less = less risk

Question 8

what causes galactorrhea?

Answer 8

production of milk outside of lactation (“nipple discharge”)

caused by increased prolactin or antagonism of dopamine (which inhibits prolactin)

Question 9

where do simple cysts of the breast occur?

Answer 9

terminal duct lobular unit - round, filled with dark fluid (appear “blue domed” on gross specimen, black hole on ultrasound)

if cyst ruptures, inflammation causes fibrosis

Question 10

how does apocrine metaplasia of the breast appear?

Answer 10

fibrocystic/ benign change in which lobular epithelial cells taken on appearance of apocrine (gland) cells

Question 11

what is the key clinical difference between fibrocystic changes of the breast and proliferative breast disorders?

Answer 11

fibrocystic changes = benign (simple cyst, fibrosis, apocrine metaplasia)

proliferative breast disorders: normal cells, but small increase in risk of breast cancer (epithelial hyperplasia, sclerosing adenosis, intraductal papilloma)

Question 12

what histological changes occur in breast epithelial hyperplasia?

Answer 12

normal ducts/lobules have 2 layers of epithelium (luminal + myoepithelium)

hyperplasia —> proliferation of more layers —> distended ducts/lobules and lumen filled with clusters of cells

Question 13

what occurs in sclerosing adenosis of the breast?

Answer 13

proliferative breast disorder (small increase in breast cancer risk) characterized by increased number of acini and dense stroma

can result in calcifications, which can be detected by mammogram

Question 14

where does intraductal papilloma of the breast occur?

Answer 14

proliferative breast disorder characterized by growth of ductal epithelial cells in the ducts or lactiferous sinuses (right behind nipple)

cells grow in finger-like projections (aka, “papilla”)

present with small mass near the nipple and bloody/serous discharge

Question 15

A women presents to her physician with complaint of bloody nipple discharge. A small mass is palpated near the nipple. A biopsy is taken which shows finger-like projections of cells. What is the most likely cause?

Answer 15

intraductal papilloma: proliferative breast disorder characterized by growth of ductal epithelial cells in the ducts or lactiferous sinuses (right behind nipple)

cells grow in finger-like projections (aka, “papilla”)

present with small mass near the nipple and bloody/serous discharge

Question 16

what is the most common benign breast tumor?

Answer 16

Fibroadenoma: masses of fibrous and glandular tissue surrounded by compressed epithelial-lined spaces, develop in breast lobules as well-defined/solid/mobile mass

appear hypoechoic on ultrasound - dark grey (but not black like cysts)

Question 17

how can ultrasound be used to differentiate between a simple breast cyst and fibroadenoma?

Answer 17

simple cysts (fibrocystic change) are filled with dark fluid and appear as black holes on ultrasound

fibroadenomas (benign tumor) appear hypoechoic on ultrasound - dark grey but not completely black

Question 18

Pt is a 33yo F presenting to her physician with concern of a solid, mobile breast mass she began to notice during pregnancy. She is otherwise asymptomatic. On ultrasound, a hypoechoic mass is seen in a lobule. A biopsy is taken which shows proliferation of fibrous and glandular tissue surrounded by compressed epithelial-lined spaces. What is the most likely diagnosis?

Answer 18

Fibroadenoma: most common benign breast tumor (premenopausal, ages 15-35)

hormone sensitive - can increase in size during menstrual cycle or pregnancy / decrease in size after menopause

Question 19

in which patients does fibroadenoma vs phyllodes tumor of the breast develop?

Answer 19

Fibroadenoma: most common benign breast tumor for premenopausal patients (ages 15-35)

Phyllodes Tumor: stromal fibroepithelial tumor (usually benign) of older women (60+yo)

Question 20

Pt is a 67yo F presenting for an annual breast exam. A mass is palpated and an ultrasound follows, which shows a mass with a mixture of grey and black areas. A biopsy is taken which reveals leaf-like growth of stroma covered by epithelial cells. What is the most likely diagnosis?

Answer 20

Phyllodes Tumor: stromal fibroepithelial tumor (usually benign) of older women (60+yo)

[“phyllodes” = leaf]

Question 21

Pt is a 64yo F with 4 children presenting with a breast mass just below the nipple that produces thick, white discharge. What is the most likely diagnosis?

Answer 21

mammary duct ectasia: benign inflammatory condition affecting older women (50+), most often multiparous (multiple children)

distention/ectasia of subareolar ducts due to chronic inflammation/fibrosis

Question 22

how does mammary duct ectasia present?

Answer 22

benign inflammatory condition affecting older women (50+), most often multiparous (multiple children)

distention/ectasia of subareolar ducts due to chronic inflammation/fibrosis

breast mass under the nipple producing thick, white discharge but no pain/erythema

Question 23

what causes fat necrosis of the breast?

Answer 23

trauma - biopsy, surgery, sports injury, etc

benign inflammatory process which can mimic breast cancer (painless mass, calcifications on mammogram)

biopsy shows fat necrosis + inflammatory cells

Question 24

what is the usual cause of acute mastitis of the breast?

Answer 24

aka lactational mastitis: trauma to skin around nipple due to frequent breast feeding —> erythema, tenderness

most commonly due to infection by staph. aureus (skin flora) - tx w/ dicloxacillin or cephalexin

mother should continue nursing (“use it or lose it”, no harm to baby)

Question 25

A new mother presents to her physician with breast erythema and tenderness around her nipple. She has been breastfeeding frequently since her child was born. She also reports recent onset of malaise and fever. She is concerned about the safety in continuing nursing. What is the most likely cause of her symptoms and how will you treat/counsel her?

Answer 25

lactational/ acute mastitis: due to trauma around the nipple and infection, most often by staph. aureus (skin flora)

treat with dicloxacillin or cephalexin and continue nursing (no harm to baby, “use it or lose it” with lactation)

Question 26

what is the usual cause of periductal mastitis?

Answer 26

aka squamous metaplasia of lactiferous ducts: inflammation of subareolar ducts in female smokers (due to toxins)

—> squamous metaplasia of cuboidal epithelium, which blocks the ducts and may cause secondary infection (may require drainage)

presents as periareolar mass with redness, tenderness, and warmth

Question 27

Pt is a 32yo F presenting with a periareolar mass of the breast which is red, tender, and warm. PMH is noncontributory but the patient smokes frequently. The mass is drained and a biopsy is done, which shows squamous metaplasia of the ductal cuboidal epithelium. What is the most likely diagnosis?

Answer 27

periductal mastitis, aka squamous metaplasia of lactiferous ducts: inflammation of subareolar ducts in female smokers (due to toxins)

—> squamous metaplasia of cuboidal epithelium, which blocks the ducts and may cause secondary infection (may require drainage)