normal anatomy of the breast

Question 1

when do mammary crests or ridges appear

Answer 1

4th week

Question 2

where do mammary crests extend to

Answer 2

These crests extend from axillary region to inguinal region

The crests usually disappear except in the pectoral region

Question 3

what do primary mammary buds extend into

Answer 3

Primary mammary buds – Secondary buds – lactiferous ducts and their branches

Question 4

who are breasts found in and what is their general function

Answer 4

Secondary sexual feature of females

Source of nutrition for the neonates

Present in a rudimentary form in males

Site of malignant change in as many as 1 in 10 women

Question 5

what are general features of breasts

Answer 5

Modified and highly specialized sweat glands

No special capsule or sheath

Both Males & females have breasts

Well developed in females

Breast size and shape result from genetic,racial, and dietary factors

Question 6

where is the breast located

Answer 6

Extent: Vertical: 2nd or 3rd rib – 6th rib

Transverse: Sternal edge to midaxillary line

Lies on the deep pectoral fascia

Axillary tail (of spence) or process – a small part of
breast may extend towards axillary fossa

Retromammary space (bursa) – helps some degree of
movement

Question 7

what anatomical components are related to the breast

Answer 7

2/3rd of the breast rests on the pectoral fascia covering pectoralis major

1/3rd of the breast rests on the fascia covering serratus anterior

Firmly attached to the dermis by suspensory ligament of cooper – help support the lobules of the gland

Question 8

nipple

Answer 8

Prominence of the breast

Question 9

areola

Answer 9

Pigmented area around the nipple

Question 10

how many lobules of glandular tissue does each breast contain

Answer 10

Each breast contains 15-20 lobules of glandular tissue (parenchyma)

Question 11

what is each lobule drained by

Answer 11

a lactiferous duct – opens independently on the nipple

Each duct has a dilated portion – lactiferous sinus

Question 12

what does the nipple contain and where is it located

Answer 12

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 13

what is the areola and how does pregnancy affect it

Answer 13

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 14

what quadrants are the breast divided into

Answer 14

For anatomical location and description of pathology (cysts and tumours) the breast is divided into 4 quadrants.

The axillary tail is an extension of breast tissue in the supero-lateral quadrant

SUPEROLATERAL
SUPEROMEDIAL
INFEROLATERAL
INFEROMEDIAL

Question 15

what are components of the male breast

Answer 15

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

Question 16

what is gynaecomastia

Answer 16

Postnatal development of rudimentary lactiferous ducts in males

During midpuberty about 2/3rd of boys develop varying degrees of hyperplasia of the breasts

Question 17

what are supernumerary breasts and nipples

Answer 17

Polymastia –An extra breast

Polythelia – An extra nipple

Question 18

what is athelia or amastia

Answer 18

Absence of nipple or breast

Question 19

what is the blood supply to the breast

Answer 19

Supplied by Branches of
axillary artery, internal thoracic, and
some intercostal arteries

Thoraco acromial artery
Lateral thoracic artery
Internal mammary (thoracic) artery

Question 20

what are the nerves of the breast

Answer 20

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 21

what is lymphatic drainage of the breast

Answer 21

Great clinical significance because metastatic dissemination occurs primarily by the lymphatic routes

Breast lymphatics branch extensively and do not contain valves

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 22

Role of sentinel lymph node (first draining node) biopsy – Breast Cancer

Answer 22

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 23

what makes up the soft tissue of the breast

Answer 23

Made up of lobes which contains a network of glandular tissue consisting of branching ducts and secretory lobules in a connective tissue stroma.

The terminal duct lobular unit is the functional milk secretory component of the breast

The connective tissue stroma that surrounds the lobules is dense and fibrocollagenous, whereas intralobular tissue has a loose texture

Question 24

what is the histological appearance of a normal breast

Answer 24

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 25

prepubertal breast changes

Answer 25

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 26

pubertal breast changes

Answer 26

Branching of lactiferous ducts

Solid, spheroidal masses of granular polyhedral cells (alveoli)

Accumulation of lipids in the adipocytes

Question 27

post menopausal breast changes

Answer 27

Progressive atrophy of lobules and ducts

Fatty replacement of glandular tissue

Question 28

what are diagnostic methods for the breast

Answer 28

Imaging –Mammography and Ultrasound

Fine needle aspiration cytology

Core biopsy

Question 29

what are examples of benign breast tumours

Answer 29

Fibroadenomas

Duct papillomas

Adenomas

Connective tissue tumours

Question 30

what is Paget’s disease of the nipple

Answer 30

Erosion of the nipple resembling eczema
Associated with ductal or invasive carcinoma