Normal Anatomy of the Breast

Question 1

breast margins

Answer 1

2nd - 6th rib
sternal edge
midaxillary line
lies on deep pectoral fascia
tail towards axillary fossa

Question 2

what attaches the breast to the dermis?

Answer 2

suspensory ligament of cooper

Question 3

how many lobules does each breast contain?

Answer 3

15-20

Question 4

what drains the breast lobules?

Answer 4

lactiferous duct

Question 5

describe the nipple

Answer 5

• No fat or hair
• Contains collagenous dense connective tissue, elastic fibres and bands of smooth muscle
• The tips of the nipples are fissured with lactiferous ducts opening into them
• Position : variable or 4th intercostal space

Question 6

describe the areola

Answer 6

• Skin covering the nipple and areola contains numerous sweat & sebaceous glands
• Enlarge during pregnancy
• Oily material secreted by the sebaceous gland provides a protective lubricant for nipple and areola

Question 7

describe the male breast

Answer 7

• Rudimentary throughout life
• Formed by small ducts without lobules or alveoli
• Little supporting fibroadipose tissue
• Temporary enlargement in newborn & during puberty

Question 8

describe the development of the breast

Answer 8

• Mammary crests or ridges appear during 4th week
• These crests extend from axillary region to inguinal region
• The crests usually disappear except in the pectoral region
• Primary mammary buds – Secondary buds – lactiferous ducts and their branches

Question 9

what is polymastia

Answer 9

an extra breast

Question 10

what is polythelia

Answer 10

an extra nipple

Question 11

what is athelia or amastia

Answer 11

absence of nipple or breast

Question 12

blood supply to the breast

Answer 12

axillary artery
internal thoracic
intercostal

Question 13

nerve supply to the breast

Answer 13

• Anterior and lateral cutaneous branches of 4- 6th intercostal nerves
• They convey sensory fibers to the skin of the breast
• They also carry sympathetic fibres to the blood vessels and to the smooth muscle around the nipple

Question 14

breast lymphatic drainage

Answer 14

Most lymph (more than 75%) from lateral quadrants – axillary lymph nodes
• Some lymph may drain directly to supraclavicular or inferior cervical nodes
• Lymph from medial quadrants – parasternal or to opposite breast

Question 15

role of the sentinel lymph node in breast cancer

Answer 15

• Lymphatic mapping & staging of patients
• A radiolabelled colloid is used to locate the sentinel node
• At the time of surgery, a vital blue dye is injected
• Combination of rodioisotope and dye provides most accurate means of localizing the node

Question 16

describe the histology of the normal breast

Answer 16

Extensive branching duct system
• Surrounded by dense fibrous interlobular tissue (F) & adipose tissue (A)
• Ducts & acini are lined by two layers of cells – Luminal epithelial cells (E) & myoepithelial cells (M)

Question 17

prepubertal breast changes

Answer 17

• Neonatal breast contain lactiferous ducts but no alveoli
• Until puberty, little branching of the ducts occurs
• Slight breast enlargement reflects the growth of fibrous stroma and fat

Question 18

pubertal breast changes

Answer 18

• Branching of lactiferous ducts
• Solid, spheroidal masses of granular polyhedral cells (alveoli)
• Accumulation of lipids in the adipocytes

Question 19

post menopausal breast changes

Answer 19

• Progressive atrophy of lobules and ducts

* Fatty replacement of glandular tissue

Question 20

describe the histology of the breast during pregnancy

Answer 20

• Enlarged lobules
• Acini are dilated
• Epithelium vary from cuboidal
to low columnar

Question 21

what is colostrum?

Answer 21

Protein rich fluid, available few days after birth – rich in maternal
antibodies

Question 22

describe the histology of a lactating breast

Answer 22

• Acini distended with milk
• Thin septa (S) between the lobules
• At higher magnification (b) – Acini with eosinophilic material containing clear vacuoles
• Milk production – Suckling -Neurohormonal reflex –Prolactin & Oxytocin

Question 23

name some benign breast tumours

Answer 23

• Fibroadenomas
• Duct papillomas
• Adenomas
• Connective tissue tumours

Question 24

what is Paget’s disease of the nipple?

Answer 24

• Erosion of the nipple resembling eczema

* Associated with ductal or invasive carcinoma