Objectives: Describe the location of the breast in relation to fascial layers Identify the extent of the base of the breast Define the reteromammary space Identify the axillary tail and its significance Understand the differences in size and colour of the areola; contractility of the nipple; Montgomery’s glands. Describe the lobes of the breast and the clinical significance of the suspensory ligaments. Describe the histological changes of the mammary gland during different phases: before puberty, inactive gland, during menstruation, active phase, and menopause. Identify myoepithelial cells and their functional significance. Understand the role of merocrine and apocrine secretion in the production of milk. Describe mammary line and its congenital anomalies: polymastia, polylethelia, inverted nipple. Identify the features of the pregnant woman’s breast Understand the features of structural involvement in breast cancer Breast features in mammography. Incising for and positioning of a breast implant. Describe the male breast and gynaecomastia. Locate the arterial blood supply and venous drainage of the breast. Describe the nerve supply and reflex secretion of milk Thorough description of the lymphatic drainage of the breast and axillary lymph nodes Applied anatomy of breast cancer metastasis, peau d’orange, and lympodema of the upper limb. Surgical anatomy of mastectomy and paralysis of the long thoracic nerve.

1. Morphology of the Mammary Gland
Dr. Akram Jaffar, Ph.D.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

2. References and further reading
 Moore KL & Dalley AF (2006): Clinically Orientated Anatomy. 5th Ed.
Lippincott, Williams & Wilkins. Philadelphia. pp: 105-111
 Snell RS (2007): Clinical anatomy by systems. Lippincott. Philadelphia.
pp:90-94
 Eroschenko VP (2005): diFiore’s Atlas of Histology with Functional
correlations. 10th ed. Lippincott Williams & Wilkins. Baltimore
 Sadler TW (2006): Langman’s Medical Embryology. 10th ed. Lippincott
Williams & Wilkins. Baltimore. pp:337-338
© Dr. Akram Jaffar
© Dr. Akram Jaffar

3. Objectives
 Describe the location of the breast in relation to fascial layers
 Identify the extent of the base of the breast
 Define the reteromammary space
 Identify the axillary tail and its significance
 Understand the differences in size and colour of the areola; contractility of the nipple;
Montgomery’s glands.
 Describe the lobes of the breast and the clinical significance of the suspensory ligaments.
 Describe the histological changes of the mammary gland during different phases: before
puberty, inactive gland, during menstruation, active phase, and menopause.
 Identify myoepithelial cells and their functional significance.
 Understand the role of merocrine and apocrine secretion in the production of milk.
 Describe mammary line and its congenital anomalies: polymastia, polylethelia, inverted nipple.
 Identify the features of the pregnant woman’s breast
 Understand the features of structural involvement in breast cancer
 Breast features in mammography.
 Incising for and positioning of a breast implant.
 Describe the male breast and gynaecomastia.
 Locate the arterial blood supply and venous drainage of the breast.
 Describe the nerve supply and reflex secretion of milk
 Thorough description of the lymphatic drainage of the breast and axillary lymph nodes
 Applied anatomy of breast cancer metastasis, peau d’orange, and lympodema of the upper limb.
© Dr. Akram Jaffar
 Surgical anatomy of mastectomy and paralysis of the long thoracic nerve.
© Dr. Akram Jaffar

4. The female breast
Superficial
fascia
 Skin gland capable of secreting milk.
 Being a skin gland, the breast is
situated in the superficial fascia and
has NO capsule.
Deep fascia
Pectoralis
Major m.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

5. Base of the breast
Pectoralis
 The breast can be easily Major m.
separated from the deep fascia
covering pectoralis major, serratus Serratus
anterior and external oblique Anterior m.
muscles on the anterior thoracic
wall.
External
Oblique m.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

6. Retromammary space
 A loose connective tissue plane or potential space
 Between the breast and the deep pectoral fascia
 Allows the breast some degree of movement.
 When breast cancer invades this space, the breast
elevates when the pectoralis major muscle contracts.
To observe this movement, the doctor asks the
patient to put her hands on her hips and press to
tense her pectoral muscles.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

7. Base of the breast
 In spite of differences in the size and shape of
the breasts, the size of the base of the breast
is fairly constant.
 The base of the breast extends
 from the 2nd to the 6th rib in the
midclavicular line
 from the edge of the sternum to the mid-
axillary line.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

8. Axillary tail
Pectoralis
 Extends upwards and laterally along the inferior Major m.
border of pectoralis major muscle.
 Contains a large amount of glandular tissue, and a
great percentage of breast tumors occur there.
tail
© Dr. Akram Jaffar
Percent distribution of breast tissue Percent distribution of breast tumor
© Dr. Akram Jaffar

9. Axillary tail
 This breast tail (of Spence) enters a hiatus (of
Langer) in the deep fascia of the medial axillary
wall.
 The only breast tissue found beneath the deep
fascia.
 May be visible as definite mass simulating an
axillary tumor
© Dr. Akram Jaffar
© Dr. Akram Jaffar

10. The areola
 Hyperpigmented area of skin
surrounding the nipple.
 Contains modified sebaceous
glands called areolar glands of
Montgomery
 The areolar glands enlarge
during pregnancy and secrete an
oily substance that protects the
areola and nipple
© Dr. Akram Jaffar
© Dr. Akram Jaffar

11. Size and color of the areola
 Variable in size and color.
 At puberty, the areola enlarges and become
more pigmented.
 The depth of color depends on the woman’s
skin color. White nulliparous
 pink in white nulliparous woman
Negro
 dark brown in Negroes
 During pregnancy, the areola enlarges and
becomes deep brown to black.
 The color diminishes after pregnancy but
never returns to the original pink color.
Pregnant
Increasing age
© Dr. Akram Jaffar
© Dr. Akram Jaffar

12. The areola
 Small collection of smooth muscle
located at the base of the nipple may
cause erection of the nipple during
nursing or sexual arousal.
Relaxed areola
© Dr. Akram Jaffar
Contracted areola
© Dr. Akram Jaffar

13. Breast lobes
gland
lobe
 There are 15-20 lobes of duct
glandular tissue.
 The lobes are separated by
fibrous tissue septa.
 Each lobe is drained by a
lactiferous duct. Fibrous
 Lactiferous ducts extend from septum
the nipple in a radial manner.
 Under the areola, each duct has
a dilated portion called
sinus
lactiferous sinus in which milk
accumulates during lactation.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

14. Suspensory ligaments
 Fibrous tissue septa that extend
from the deep fascia to the skin
are called the suspensory
ligaments of the breast (ligaments
of Cooper).
 Maintain the breast form in the
upright posture.
 Less effective when a person lies
on her back
© Dr. Akram Jaffar
© Dr. Akram Jaffar

15. Suspensory ligaments
 Malignant infiltration of the suspensory ligaments causes their shortening and
invagination (dimpling) of the overlying skin
Deep fascia
Suspensory
ligament
© Dr. Akram Jaffar
© Dr. Akram Jaffar

16. Suspensory ligaments
 Abscess in the breast is preferably opened by a radial incision to avoid cutting across
a number of lactiferous ducts (being radially arranged) and to prevent spread of
infection from one lobe to another across the borders (suspensory ligaments).
© Dr. Akram Jaffar
Breast abscess Breast abscess drainage Breast lobes
© Dr. Akram Jaffar

17. Histology of the mammary gland
 Compound alveolar gland
© Dr. Akram Jaffar
© Dr. Akram Jaffar

18. Histology of the inactive gland
 Abundant connective
tissue Ducts
 The sparse glandular lobule
component consists chiefly
Dense CT
of ducts.
 Ducts are surrounded by a
loose connective tissue Loose CT
containing lymphocytes,
plasma cells and
fibroblasts.
 The ducts and surrounding
loose connective tissue
constitute a lobule.
 Beyond a lobule, the
connective tissue is more
dense Adipose tissue
 The dense connective
© Dr. Akram Jaffar
tissue contains aggregates
of adipocytes.
© Dr. Akram Jaffar

19. Histology of the tubular portion
 The lactiferous ducts are lined with stratified squamous epithelium near their openings
at the nipple.
 In the lactiferous sinus, the lining is stratified cuboidal.
 The remainder of the duct system is lined by a single layer of columnar or cuboidal cells.
Columnar - cuboidal
Stratified cuboidal
© Dr. Akram Jaffar
© Dr. Akram Jaffar

20. Myoepithelial cells
 Cells of ectodermal origin
 Lie within the epithelium between the
surface epithelial cells and the basal
lamina.
 Are present in the ductal and secretory
portion of the gland.
Loose CT cells
© Dr. Akram Jaffar
Myoepithelial cell
Basal lamina
© Dr. Akram Jaffar

21. Histological changes
 Changes during the menstrual cycle
 Early in the cycle, the ducts appear as cords with little or no lumen.
 Under estrogen stimulation, at about the time of ovulation, the secretory cells
increase in height, lumina appear in the ducts as small amounts of secretions
accumulate, and fluid accumulates in the connective tissue.
 Changes in preparation for lactation:
 Decrease in the amount of connective tissue and adipose tissue.
 Plasma cells, lymphocytes, and eosinophils infiltrate the fibrous component of
the connective tissue.
 Development of glandular tissue: cells proliferate by mitotic division, the ducts
branch and alveoli begin to develop.
 In the later stages of pregnancy, alveolar development becomes more
prominent. The actual proliferation of the stromal cells declines, and subsequent
enlargement of the breast occurs through hypertrophy of the secretory cells and
accumulation of secretory product in the alveoli.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

22. Histological changes
 Changes after menopause.
 Degeneration of glandular tissue but some ducts may remain
 Degeneration of connective tissue: decrease in the number of fibroblasts and
collagen fibers, and loss of elastic fibers  pendulous breast.
 During puberty
 Enlargement mainly from increased fat deposition and partly from glandular
development
© Dr. Akram Jaffar
© Dr. Akram Jaffar

23. Histology of the active (lactating) gland
 Individual lobules are separated by narrow dense connective tissue septa
 The connective tissue within a lobule is loose connective tissue that is now containing
more lymphocytes and plasma cells.
 The ducts and alveoli are well developed, secretory products may be seen in the lumen
 Alveoli show irregular branching pattern
Branching alveoli
Glandular tissue
Secretory product
Dense CT
Plasma cell
© Dr. Akram Jaffar
lymphocyte
© Dr. Akram Jaffar

24. Method of secretion
 The protein component of the milk.
 Merocrine secretion: secretory vesicles coalesce with the membrane on the
apical surface to release the product:
 The lipid component of the milk
 Apocrine secretion. lipid droplets pass to the apical region of the cell. The
droplets are invested with an envelope of plasma membrane and a thin layer of
cytoplasm as they are released into the lumen of the acini.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

25. Embryology
 The first indication of mammary glands
is a band-like thickening of epidermis,
the mammary (milk) line.
 The milk line extends from the upper
thigh superiorly to the axilla.
 The major part disappears.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

26. Embryology
 In the thoracic region, a small portion
penetrates the mesenchyme, forms
sprouts which give rise to a small solid
bud.
 The sprouts are canalized  lactiferous
ducts  small ducts and alveoli.
 Initially, the ducts open into a small
epithelial pit. The pit proliferates into a
nipple after birth
© Dr. Akram Jaffar
© Dr. Akram Jaffar

27. Comparative anatomy
 In many mammals (cats, dogs, etc.), the milk
line persists as fully formed mammary glands,
but in humans only one breast on each side
develops.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

28. Polythelia (supernumerary nipple)
 Accessory nipples are formed due to the
persistence of mammary line.
 May develop anywhere along the original line
but usually in the axilla.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

29. Polymastia
 Occasionally, a supernumerary (i.e. extra) breast may develop along this milk line.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

30. Inverted nipple
 In many women, the original epithelial pit fail to evert.
 Retraction of the nipple, if a new occurrence should have a
high index of suspicion for a malignancy.
 When congenitally retracted, this should not be a cause for
concern except when preparing to breast-feed. This can often
be assisted by nipple shields, which revert the retracted
nipple.
Congenital retraction
© Dr. Akram Jaffar
Retracted nipple + tumor
© Dr. Akram Jaffar

31. Features of a pregnant woman’s breast
 The whole breast is enlarged and the axillary tail is noticeable
 Dilated veins can be seen over the breast skin
 The nipple and areola are deeply pigmented
 Areolar glands increase in number and size
© Dr. Akram Jaffar
© Dr. Akram Jaffar

32. External features of breast cancer
© Dr. Akram Jaffar
© Dr. Akram Jaffar

33. Mammography
 A low-powered x-ray technique that gives a picture of
the internal structure of the breast.
 May help in the diagnosis of breast problems including
cancer
Mammogram
© Dr. Akram Jaffar
Technique
© Dr. Akram Jaffar

34. Breast implantation
 A surgical procedure for enlarging the breast.
 Breast-shaped sacks made of a silicone outer shell
and filled with silicone gel or saline are used.
 The incision is made through the axilla, under the
breast, or around the areola to create the most
inconspicuous scars.
 The implant is placed between the breast tissue and
underlying pectoralis major muscle, or under the
pectoralis major muscle.
Position of the implant
© Dr. Akram Jaffar
Sites for the incision
© Dr. Akram Jaffar

35. The male breast
 During embryologic development, growth and development of breast tissue occur in
both sexes.
 In males, little additional development of the mammary glands occurs in postnatal
life, and the glands remain rudimentary.
 Has similar structure to immature female’s breast.
 The nipples are small.
 The breast tissue consists of a system of ducts embedded in connective tissue.
 The breast tissue does not extend beyond the margin of the areola
 May be affected by breast cancer
© Dr. Akram Jaffar
© Dr. Akram Jaffar

36. Gynecomastia
 Activation and hypertrophy of the breast tissue in men.
 It can occur frequently in young men (pubertal hypertrophy) and in older men.
 It can also be caused by numerous medications and hormones
© Dr. Akram Jaffar
© Dr. Akram Jaffar

37. Innervation
 Anterior and lateral cutaneous branches from the second to sixth intercostal nerves:
cutaneous and sympathetic innervation (blood vessels and smooth muscle of skin
and nipple).
 The secretory function is primarily under hormonal control, but afferent impulses
associated with suckling are involved in the reflex secretion of prolactin and oxytocin.
 Suckling during breast-feeding initiates sensory impulses from receptors in the nipple
to the hypothalamus  prolactin release from the adenohypophysis.
 The sensory impulses also cause the release of oxytocin in the neurohypophysis.
Oxytocin stimulates the myoepithelial cells that surround the base of the alveolar
secretory cells and the base of the cells in the larger ducts, causing them to contract
and eject the milk from the alveoli and the ducts.
 The milk is secreted into – not sucked from the gland by – the baby’s mouth.
 In the absence of suckling, secretion of milk ceases, and the mammary glands begin
to regress. The glandular tissue then returns to an inactive condition.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

38. Arterial supply
 Internal thoracic artery via perforating Internal
Thoracic a.
(mammary) branches that perforate
pectoralis major muscle.
 At the 2nd-4th intercostal spaces these
perforating branches are particularly large.
 The internal thoracic branches supply
most of the blood to the breast.
Pectoralis
Major m.
Perforating a.
© Dr. Akram Jaffar
Internal
Thoracic a.
Perforating a.
© Dr. Akram Jaffar

39. Arterial supply
Superior
Thoracic a.
 Axillary artery: Thoraco-acromial a.
 Lateral thoracic artery.
 Pectoral branch of the thoraco-
acromial artery
 Suprior thoracic artery
Lateral thoracic a.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

40. Arterial supply
 Posterior intercostal arteries
via lateral perforating
branches
Post. intercostal a.
Perforating a.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

41. Venous drainage
 The venous drainage is to the
veins corresponding the arteries Internal
Thoracic v.
 The chief venous drainage is
towards the axilla
 The intercostal veins
communicate posteriorly with
the vertebral venous plexus, To axillary v.
which enters the azygos veins
and eventually the superior
vena cava. By this pathway SVC
metastasis may travel to the
Azygos v.
skeleton and central nervous
system
 venous spread of breast cancer
may reach the liver through
porto-caval anastomoses
Post. Intercostal v.
Internal vertebral
Venous plexus
© Dr. Akram Jaffar
© Dr. Akram Jaffar

42. Lymphatic drainage
Axillary LNs
 Axillary vessels to axillary lymph nodes
which constitute the major drainage
area for the breast.
 Internal thoracic vessels to parasternal
lymph nodes located along these
vessels.
 There is a tendency for the lateral part
of the breast to drain towards the axilla
and the medial part to the parasternal
group.
 Most carcinomas of the breast occur in
the upper lateral quadrant and thus Parasternal LNs
undergo metastasis to axillary lymph
nodes
© Dr. Akram Jaffar
© Dr. Akram Jaffar

43. Lymphatic drainage
 Obstruction of the usual lymphatic
pathway by malignant cells will
cause cancer cells to pass along
uncommon channels:
 Infraclavicular lymph nodes
 Contralateral breast
 Anterior abdominal wall
© Dr. Akram Jaffar
© Dr. Akram Jaffar

44. Peau d’orange
 Blockage of the lymph drainage of
the skin overlying the tumor causes
edema
 The skin is thickened and prominent
between dimpled pores.
 The skin looks like an orange peel
(peau d’orange).
© Dr. Akram Jaffar
© Dr. Akram Jaffar

45. Axillary lymph nodes
 Drain not only the breast but also
 The pectoral region
 Upper part of the abdominal wall
 Upper part of the back
 The upper limb
© Dr. Akram Jaffar
© Dr. Akram Jaffar

46. Axillary lymph nodes
apical gp
Central gp
Pectoralis
Minor m.
Axillary v.
 Axillary lymph nodes are arranged
in five groups
 Anterior or pectoral group lying
deep to pectoralis major along the
inferior border of pectoralis minor
muscle: drain most of the lymph of
the breast
 Posterior or subscapular group, lie
in front of subscapularis on the
posterior wall of the axilla .
 Lateral group lying along the
axillary vein
 Central group lying in the axillary
Anterior gp.
fat
 Apical group lying behind the
posterior gp.
© Dr. Akram Jaffar
clavicle at the apex of the axilla
lateral gp.
© Dr. Akram Jaffar

47. Examination of axillary lymph nodes
Posterior group
Central group
© Dr. Akram Jaffar
Pectoral group
© Dr. Akram Jaffar

48. Lymphoedema
 The axillary lymph nodes are often
removed or irradiated during treatment
of breast cancer, in such a case
lymphoedema in the upper limb follows
because axillary lymph nodes drain the
upper limb in addition to the breast.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

49. Surgical anatomy of mastectomy
 Three types of mastectomy:
 Radical mastectomy:
Removal of the breast,
axillary lymph nodes,
pectoralis major and minor
 Modified radical
mastectomy: Removal of the
breast and axillary lymph
nodes
 Simple mastectomy:
Removal of the breast only.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

50. Triangular bed of radical mastectomy
Pectoralis
minor m.
Axillary v.
Subscapular nn
Long thoracic n.
Thoracodorsal n.
Serratus
Latissimus Ant. m.
Dorsi m.
Subscapularis m.
Pectoralis
Major m.
© Dr. Akram Jaffar
© Dr. Akram Jaffar

51. Long thoracic nerve
 seen in the pectoral region on
 a branch of brachial plexus C5,6, & 7. It is the surface of serratus anterior
also called the nerve of Bell just behind the mid axillary line,
supplying the muscle
 May be injured during radical mastectomy
© Dr. Akram Jaffar
© Dr. Akram Jaffar

52. Long thoracic nerve injury Winged scapula
 When the serratus anterior is paralyzed, the medial
border of the scapula appears to be projecting
backwards giving the appearance of a wing when the
patient presses against a wall
3 2
trapezius deltoid
1
supraspinatus
 In addition, the patient is unable to raise
his/her arm above the head owing to
© Dr. Akram Jaffar
inability to rotate the scapula during
abduction of the arms above a right angle
3 3
trapezius serratus anterior
© Dr. Akram Jaffar