B8-035 Breast Histology & Physiology

Question 1

[hormone] stimulates the development of the lactiferous ducts

Answer 1

estrogen

(with prolactin)

Question 2

[hormone] stimulates the development of the lobules

Answer 2

progesterone

Question 3

only with […] does the breast fully mature

Answer 3

pregnancy

Question 4

milk production in pregnancy is inhibited by [hormone]

Answer 4

progesterone

Question 5

rising levels of [hormone] throughout pregnancy increases prolactin secretion

Answer 5

estrogen

Question 6

suckling of the infant causes the release of [hormone], causing milk ejection by contraction of the myoepithelial cells

Answer 6

oxytocin

Question 7

surrounds the glands and ducts with connective and adipose tissue

Answer 7

Interlobular mammary stroma

Question 8

Basic histopathological units of the mammary gland

Answer 8

Terminal ductal lobular units (TDLU)

Question 9

loose, cell-rich connective tissue within the TDLU

Answer 9

Intralobular stroma

Question 10

Outer layer of the TDLU is comprised of […] cells that are contractile and route the milk to the ducts in lactating breasts

Answer 10

myoepithelial

Question 11

the Inner layer of the TDLU is comprised of cubic, apocrine glandular […] epithelial cells that can produce milk

Answer 11

luminal

Question 12

distinct histological features of a lactating breast

Answer 12

very large lobules with tubulo-alveolar ends
small amounts of interlobular connective tissue

Question 13

what changes to the breast are occurring in the proliferative phase of the menstrual cycle?

Answer 13

no changes

Question 14

what changes to the breast are occurring in the secretory phase of the menstrual cycle?

Answer 14

↑ estrogen and ↑ progesterone → cell proliferation, ↑ number of acini, edema of interlobular stroma

Question 15

what changes to the breast are occurring during menstruation?

Answer 15

desquamation and regression

Question 16

what changes in the breast occur due to age? [4]

Answer 16

involution of the breasts due to a decrease in estrogen levels

Atrophy of mammary glands and connective tissue stroma

The milk duct system is preserved.

Relative increase in fat percentage due to replacement of stroma with fat

Question 17

main mammographic signs of breast carcinoma [2]

Answer 17

densities
calcifications

Question 18

most common causative agent of mastitis

Answer 18

S. aureus

Question 19

squamous metaplasia of lactiferous ducts (SMOLD) has a strong association with […]

Answer 19

smoking

Question 20

painful, erythematous subareolar mass
may be interpreted clinically as an abscess

Answer 20

squamous metaplasia of lactiferous ducts (SMOLD)

Question 21

epithelium extends into ducts, keratin accumulates and ruptures causing inflammatory response

Answer 21

squamous metaplasia of lactiferous ducts (SMOLD)

Question 22

post-menopausal women with unilateral nipple pain/bleeding

dilated ducts with lipid secretions and foamy histiocytes on microscopy

Answer 22

mammary duct ectasia

Question 23

early lesions have hemorrhage and indurated fat

later, necrotic fat cells surrounded by lipid filled macrophages and neutrophils

Answer 23

fat necrosis

(commonly associated with trauma)

Question 24

fibrocystic change has […] risk of developing into breast cancer

Answer 24

low

Question 25

3 principle morphologic changes of fibrocystic change

Answer 25

1. cystic change/apocrine metaplasia: lobules dilate or join into larger cysts 2. fibrosis from cyst rupture 3. adenosis: increase in number of acini per lobule

Question 26

blue dome cyst

Answer 26

fibrocystic change

Question 27

benign epithelial proliferation of duct slit-like fenestrations on sides of duct

Answer 27

usual ductal hyperplasia (low risk of developing invasive breast cancer)

Question 28

acini and stomal fibrosis with microcalcifications

Answer 28

sclerosing adenosis (low risk of developing invasive breast cancer)

Question 29

benign lesion with fibroelastosis and entrapped glandular structures may mimic invasive carcinoma on imaging due to stellate appearance

Answer 29

radial scar/complex sclerosing lesion (associated with intraductal hyperplasia)

Question 30

small fibroepithelial tumor within lactiferous ducts, typically beneath areola most common cause of nipple discharge

Answer 30

intraductal papilloma (2-3x risk of invasive breast carcinoma)

Question 31

very very similar to low grade DCIS, but small amount and not well developed

Answer 31

atypical ductal hyperplasia (close follow up due to increased risk of invasive cancer)

Question 32

non-invasive neoplastic proliferation of small, dyscohesive cells expanding less than 50% of the TDLU

Answer 32

atypical lobular hyperplasia (ALH) (4-5x risk of invasive breast cancer)

Question 33

[...] make milk that drains via ducts to the nipple

Answer 33

lobules

Question 34

The [...] is the functional unit of the breast

Answer 34

terminal duct lobular unit

Question 35

Lobules and ducts are lined by [...] layers of epithelium

Answer 35

two luminal cell layer and myoepithelium

Question 36

inner cell layer lining the ducts and lobules; responsible for milk production in the lobules

Answer 36

luminal cell layer

Question 37

outer cell layer lining ducts and lobules; contractile function propels milk towards the nipple.

Answer 37

myoepithelial cell layer

Question 38

During pregnancy, breast lobules undergo [...]

Answer 38

hyperplasia

Question 39

after menopause, breast tissue undergoes [...]

Answer 39

atrophy

Question 40

Inflammation of the subareolar ducts Usually seen in smokers Clinically presents as a subareolar mass with nipple retraction

Answer 40

periductal mastitis

Question 41

Inflammation with dilation of the subareolar ducts classically arises in multiparous postmenopausal women

Answer 41

mammary duct ectasia

Question 42

Presents as a periareolar mass with green-brown nipple discharge Chronic inflammation with plasma cells is seen on biopsy

Answer 42

mammary duct ectasia

Question 43

Papillary growth, usually into a large duct

Answer 43

intraductal papilloma

Question 44

Characterized by fibrovascular projections lined by epithelial (luminal) **and** myoepithelial cells

Answer 44

intraductal papilloma

Question 45

Classically presents as bloody nipple discharge in a premenopausal woman Must be distinguished from papillary carcinoma, which also presents as bloody nipple discharge

Answer 45

intraductal papilloma

Question 46

characterized by fibrovascular projections lined by luminal epithelial cells **without** underlying myoepithelial cells.

Answer 46

papillary carcinoma

Question 47

Fibroadenoma-like tumor with overgrowth of the fibrous component; characteristic 'leaf-like' projections are seen on biopsy

Answer 47

phyllodes tumor (can sometimes be malignant)

Question 48

during pregnancy, milk production is inhibited my high levels of [...]

Answer 48

progesterone

Question 49

[...] causes ejaculation of milk through myoepithelial cells

Answer 49

oxytocin

Question 50

do breast TDLUs remain the same throughout the menstrual cycle?

Answer 50

no, fluctuate with ovulation

Question 51

male and female breast histology are [same/different] pre-puberty

Answer 51

same

Question 52

how do breast TDLUs change after cessation of lactation?

Answer 52

regress

Question 53

the most common etiology for nipple discharge is

Answer 53

solitary large duct papilloma

Question 54

bloody or serous nipples discharges are more commonly associated with [benign/malignant] lesions

Answer 54

benign

Question 55

milky nipple discharge [is/is not] associated with malignancy

Answer 55

is not

Question 56

the risk of malignancy with nipple discharge increases with [...]

Answer 56

age

Question 57

usual ductal hyperplasia carries a 1-2% risk of developing malignancy in [one/both] breasts

Answer 57

both (follow up with routine mammogram)

Question 58

management of usual ductal hyperplasia

Answer 58

follow up with routine mammograms

Question 59

poorly defined periareolar mass with thick, cheesy nipple secretion

Answer 59

duct ectasia

Question 60

dilated duct with multiple branching fibrovascular cores lined by luminal and myoepithelial cells

Answer 60

intraductal papilloma

Question 61

"lumpy bumpy" breast with microcalcifications, cysts, apocrine metaplasia, and fibrosis

Answer 61

fibrocystic changes

Question 62

unilateral, erythematous, painful breast mass biopsy shows neutrophils

Answer 62

acute mastitis