The document provides details on the anatomy of the female breast: - The breast is made up of 15-20 lobules of glandular tissue embedded in fat, separated by fibrous septa and ligaments. Each lobule drains into lactiferous ducts that empty into the nipple. - The blood supply comes from branches of the axillary, internal thoracic, and intercostal arteries. Lymphatic drainage is primarily to the axillary nodes but also to internal mammary nodes. - During pregnancy and lactation, the breast enlarges as alveoli develop from the ducts to produce milk. After weaning or menopause, the secretory tissue undergoes involution.

1. +
Anatomy of the breastDr. Kawita Bapat
Breast committee FOGSI

3. +
 Modified sweat gland- modified apocrine gland
 Made up of 15–20 lobules of glandular tissue embedded in fat.
 Fat accounts for its smooth contour and most of its bulk.
 These lobules are separated by fibrous septa running from the
subcutaneous tissues to the fascia of the chest wall (the
ligaments of Cooper/ Astley Cooper fibers/ suspensory
ligaments)
 Between the capsule and the fascia over pectoralis major is the
loose connective tissue of the retromammary space.

4. +
 Each lobule drains by its lactiferous duct on to the nipple, which
is surrounded by the pigmented areola.
 This area is lubricated by the areolar glands of Montgomery
 large,
 modified sebaceous glands →may form sebaceous cysts → may
infected.

5. +
Surface anatomy

6. +
Naming the quadrants for the purpose of
describing a lump
 Or
1. Upper medial quadrant
2. Upper lateral quadrant
3. Lower medial quadrant
4. Lower lateral quadrant

7. +
Position & extent
 2/3 rests on pectoralis major,
 1/3 on serratus anterior,
 while its lower medial edge just
overlaps the upper part of the
rectus sheath.

9. + Cross section

11. + Blood supply

12. +
 Axillary artery →
 Lateral thoracic (mainly)
 Acromiothoracic branches.
 Internal thoracic (internal mammary) artery → perforating
branches; these pierce the 1st – 4th intercostal spaces, then
traverse pectoralis major to reach the breast along its medial
edge. The 1st & 2nd perforators are the largest of these
branches.
 Intercostal arteries → lateral perforating branches- relatively
unimportant source.

13. +
Venous drainage

14. +
Venous drainage
 Sub areolar venous plexus
 Posterior intercostal veins communicate with internal vertebral
venous plexus veins - therefore cancers can spread to
vertebra- may cause back pain

15. + Lymphatic drainage

17. +
 Follows the pathway of its blood supply
 along tributaries of the
1. axillary vessels → axillary lymph nodes;
2. internal thoracic vessels → piercing pectoralis major → to
traverse each intercostal space → to lymph nodes along the
internal mammary chain; these also receive lymphatics
penetrating along the lateral perforating branches of the
intercostal vessels.

18. +
 A subareolar plexus of lymphatics below the nipple (the plexus
of Sappey)
 75% → axillary
 15% → internal mammary
 Upper → can go to supraclavicular
 Lower 2 quadrants can go to subdiapragmatic or abdominal
nodes

20. + Dermatomal supply

21. +
Development and structure
 Begins to develop as early as the 4th week as a downgrowth
from a thickened mammary ridge (milk line) of ectoderm along
a line from the axilla to the inguinal region.
 Supernumerary nipples or even glands proper may form at
lower levels on this line.
 Lobule formation occurs only in the female breast & does so
after puberty.
 Each lactiferous duct is connected to a tree-like system of
ducts and lobules, intermingled & enclosed by connective
tissue to form a lobe of the gland.

23. +
 The resting (non-lactating) breast, however consists mostly of
fibrous & fatty tissue; variations in size are due to variations in
fat content, not glandular tissue which is very sparse.
 During pregnancy alveoli bud off from the smaller ducts & the
organ usually enlarges significantly, & more so in preparation
for lactation.
 When lactation ceases there is involution of secretory tissue.
 After menopause progressive atrophy of lobes & ducts takes
place.

24. +
The male breast
 Resembles the rudimentary female breast
 has NO lobules or alveoli.
 The small nipple and areola lie over the 4th intercostal space.

25. +
Test your knowledge

26. +
1. The retromammary space is located
between which of the following
structures?
(A) skin and the areola
(B) pectoralis major and minor
(C) breast and deep pectoral fascia
(D) suspensory ligament and the skin
(E) lactiferous sinus and the nipple

27. +
Answer
(C) Between the breast and deep pectoral fascia is a loose
connective tissue plane or potential space known as the
retromammary space

28. +
2.The mammary glands are modified
versions of which type of gland?
 (A) sebaceous gland
 (B) lymph gland
 (C) sweat gland
 (D) tonsillar tissue
 (E) endocrine gland

29. +
Answer
(C) The mammary glands are modified sweat glands

30. +
3. Which of the following does NOT
supply the breast with blood?
 (A) lateral thoracic artery
 (B) thoracoacromial artery
 (C) posterior intercostals arteries
 (D) internal thoracic artery
 (E) costoclavicular artery

31. +
Answer
 (E) The breast is supplied by the
1. internal thoracic,
2. lateral thoracic,
3. thoracoacromial, and posterior
4. intercostal arteries

32. +
4. The high death rate associated with
breast cancer is related to which of the
following?
 (A) nerve supply
 (B) blood supply
 (C) venous drainage
 (D) poor imaging techniques
 (E) complex lymphatic drainage

33. +
Answer
 (E) Because the axillary lymph nodes are the most common
site of metastases from a breast cancer, enlargement of the
palpable nodes in a woman suggests the possibility of breast
cancer and may be key to early detection.
 However, the absence of enlarged axillary nodes is no
guarantee that metastasis from a breast cancer has not
occurred, because the malignant cells may have passed to
other nodes, such as the infraclavicular and supraclavicular
lymph nodes

34. +
5. Which statement most appropriately
describes the female breast?
1. It overlies the 3rd to 8th ribs.
2. It consists of 2–3 lobules.
3. It has suspensory ligaments, which tether
the dermis to the fascia of the chest wall.
4. The retro-mammary space lies deep to
pectoralis major.
5. The areolar glands are responsible for
lactation.

35. +
Answer
 c. The dermis is tethered to the breast ducts and the deep
fascia overlying pectoralis major by fibrous strands known as
the suspensory ligaments of Cooper. As these atrophy and
weaken with age the breast becomes more pendulous.

36. + Explanations
 a. The base of the adult female breast consistently overlies the 2nd to
6th ribs, from the sternal edge to the midaxillary line. The upper outer
quadrant extends towards the axilla as the “axillary tail”.
 b. The breast consists of 15–20 lobules of glandular tissue, all
individually drained by a corresponding lactiferous duct, which empty at
the nipple via the lactiferous sinus.
 d. The retro-mammary space is located between the posterior capsule
of the breast and the fascia over pectoralis major. This space is
commonly exploited in the placement of implants.
 e. The areolar glands of Montgomery are modified sebaceous glands
located beneath the areola and are responsible for lubricating the area.
These glands may enlarge or become infected, especially during
pregnancy.

37. +
6. Which of these statements are true
considering the vasculature and
lymphatic drainage of the breast?
1. The main blood supply is derived from
branches of the internal mammary artery.
2. Venous drainage is predominantly to the
internal mammary vein.
3. Lymphatic drainage is divided evenly
between the axillary and internal
mammary nodes.
4. The superficial lymphatics of each breast
remain separate in healthy people.

38. +
Answer
 e. There are five main groups of nodes in the axilla. The
anterior, posterior, lateral and central groups empty into the
apical group. The apical nodes drain into the subclavian lymph
trunk.

39. +
 Explanations
 a. The main supply is via the lateral thoracic and thoracoacromial
branches of the axillary artery. The internal mammary (internal
thoracic) artery supplies a significant part of the medial aspect via
perforating branches. The posterior intercostal arteries also make a
minor contribution.
 b. Venous drainage follows the arterial supply of the breast and is
primarily to the axillary vein.
 c. Approximately 75% of drainage is to the axillary lymph nodes,
primarily to the anterior group. The majority of the remaining drainage,
especially of the medial part, is to the internal mammary nodes.
 d. The superficial lymphatics have connections with the opposite
breast and anterior abdominal wall. If the normal drainage channels
become obstructed by malignant disease, metastatic spread may,
therefore, occur to the contralateral breast or axillary nodes.

40. +
Name the anatomical structure/s
involved
 Pt who is found to have a breast lump also having a lump in the
axilla?
 LN enlargement
 There is a dimpling of the overlying skin of the breast
 Suspensory ligaments of Cooper- lump is pulling down the
fibers.
 You suspect it is malignant & try to move the lump while the pt
presses her hip with her hands. Lump movement reduces.
 Involvement of the pectoralis major & fascia

41. +
 What directions would you move the lump?
 Diagonally to the midline

42. +
 Pt is now undergoing a mastectomy. Surgeon found LN
involvement. He wants to assess the level of involvement.
What is the landmark would you choose?
 Pectoralis minor

43. +
 If she is willing to reconstruct the breast, what muscles can be
used?
 Latissimus dorsi muscle (an LD flap)
 Transversus abdominis muscle (TRAM flap)

44. +
 Now the Pt has undergone the L/S mastectomy. She complains
of L/S upper limb swelling.
 Removal of axillary LNs which drains L/s upper limb
lymphatics
 Pt also complains of parasthesia of the left axillae
 Damage to the left intercostobrachial nerve

45. +
 Thank you!