Anatomy of breast

1. THE BREAST

2. I. Introduction/General Information
A. Embryologically: belong to integument
B. Functionally: part of reproductive
system
1. Respond to sexual stimulation
2. Feed babies

3. Breast, continued …
C. Modified apocrine sweat glands
- apex of cell becomes part of secretion
and breaks off
D. Present in males and females

4. II. Anatomy
A. Position and Attachment
1.
2.
3.
4.
5.
Lateral aspect of pectoral region
Located between ribs 3 and 6/7
Extend form sternum to axilla
Surrounded by superficial fascia
Rest on deep fascia

5. Breast Anatomy

6. Position & attachment, continued ….
6. Fixed to skin & underlying
fascia by fibrous C.T. bands
a. Cooper’s (Suspensory)
Ligaments
b. Ligaments may retract when
breast tumors are present

7. Cooper’s Suspensory Ligaments

8. Position & attachment, continued …
6. Left breast is usually slightly larger
7. Base is circular, either flattened or
concave
8. Separated from pectoralis major
muscle by fascia, retromammary
space

9. Retromammary Space
Retromammary
Space

10. Anatomy, continued …
B. Structure
1. Outer surface convex, skin covered
2. Nipple:
a. At fourth intercostal space
b. Small conical/cylindrical
prominence below center

11. Nipple location
4th
intercostal
space

12. Structure, continued …
c. Surrounded by areola: pigmented
ring of skin
d. Thin skinned region lacking hair,
sweat glands
e. Contains areolar glands

13. Structure, continued …
3. Areola: contains dark pigment that
intensifies with pregnancy
a. Circular and radial smooth muscle
fibers
b. Cause nipple erection

14. Areola

15. Structure, continued …
4. Each breast consists of ~ 20 lobes
of secretory tissue
a. Each lobe has one lactiferous duct
b. Lobes (and ducts) arranged radially
c. Embedded in connective tissue &
adipose of superficial fascia
d. Lobes composed of lobules
e. Lobules comprise alveoli

16. Lobes and Lobules

17. Structure, continued …
5. Excretory (lactiferous) ducts converge
toward areola
a. Form ampullae (collection sites of
lactiferous sinuses)
b. Ducts become contracted at base of
nipple

18. Excretory (lactiferous) ducts

19. Structure, continued …
6. Secretory epithelium
a. Changes with hormonal signals
b. Onset of menstruation
c. Pregnancy (glands begin to
enlarge at 2nd month)
d. After birth, 1st secretion is
colostrom (contain antibodies)

20. Structure, continued …
7. “Tail of Spence” = axillary tail
a. prolongation of upper, outer
quadrant in axillary direction
b. Passes under axillary fascia
c. May be mistaken for axillary lymph
nodes

21. “Tail of Spence”
Axillary Tail

22. Structure, continued …
8. Fatty Tissue: surrounds surface, fills
spaces between lobes
a. Determines form & size of breast
b. No fatty deposit under nipple &
areola

23. Breast: Fatty Tissue

24. Structure, continued …
C. Vessels & nerves
1. Arteries: derived from thoracic
branches of three pairs of arteries
a. Axillary arteries
1) continuous with subclavian a.
2) gives rise to external mammary
( = lateral thoracic) artery

25. Vessels & Nerves, continued …
b. Internal mammary (thoracic) arteries
1) first descending branch of
subclavian artery
2) supply intercostal spaces & breast
3) used for coronary bypass surgery
c. Intercostal arteries:
1) numerous branches from internal
& external mammary arteries
2) supply intercostal spaces & breast

26. Arterial Supply to the Breast
Subclavian a.
Axillary a.
External
mammary
(thoracic) a.
Internal
mammary
(thoracic) a.

27. Vessels & Nerves, continued …
2. Veins:
a. form a ring around the base of the
nipple (“circulus venosus”)
b. Large veins pass from circulus
venosus to circumference of
mammary gland, then to
c. External mammary v to axillary v
or
d. Internal mammary v to subclavian v

28. Veins draining the Breast
Subclavian vein
External
mammary vein

29. Breast Anatomy, con’t…
3. Innervation: derived from:
a. anterior & lateral cutaneous
nerves of thorax
b. spinal segments T3 – T6

30. Structure, continued …
4. Lymphatics: clinically significant!

a. Glandular lymphatics drain into
anterior axillary (pectoral) nodes
central axillary nodes 
apical nodes 
deep cervical nodes 
subclavicular (subclavian) nodes
b. Medial quadrants drain into
parasternal nodes

31. Lymph Nodes of the Breast
Subclavian
nodes
Axillary
nodes
Lateral
pectoral
nodes
Parasternal
nodes

32. Lymphatics, continued …
c. Superficial regions of skin, areola,
nipples:
-form large channels & drain into
pectoral nodes
d. NOTE: axillary nodes also drain lymph
from arm

33. Lymph Nodes and Lymph Drainage
Axillary
Nodes

34. Routes of Metastasis
From medial lymphatics to parasternal nodes
Then to mediastinal nodes
Across the sternum in lymphatics to
opposite side via cross-mammary pathways
Then to contralateral breast
From subdiaphragmatic lymphatics to nodes in abdomen
Then to liver, ovaries, peritoneum

35. Major Routes of Metastasis
Channels to Contralateral Breast
Axillary Lymph Channels
Subdiaphragmatic Lymph Channels

36. Structure, continued …
D. Anomalies
1. Inverted nipple: congenital or due
to cancer
2. Ectopic nipple:
a. “polythelia” or “hyperthelia”
b. additional nipples along milk line
3. Amastia
4. Micromastia

37. Anomalies, continued …
5. Macromastia
6. Gynecomastia
a. breast development of male in
areolar region
b. noted in males who smoke
marijuana at puberty

38. III. Diseases of the Breast
A. Most are readily detectable
B. Etiology unknown, influencing factors
1. Sex
2. Heredity

39. Diseases of the breast, continued …
3. Endocrine influence
a. Menstruation – tenderness from
fluid engorgement
b. Post-menopause
1) decrease of fibro-cystic disease
2) increase in cancer
c. Pregnancy

40. Diseases of the Breast, continued …
C. General symptoms & signs
1. Nipple discharge
a. always significant if not pregnant.
b. May be due to benign pituitary tumor.
2. Local pain, tenderness
3. Duration of lesion
4. Size, rate of growth

41. Symptoms & Signs, continued …
5. Retraction sign: “dimpling” involving
skin, nipple or areola
6. Mobility of mass
a. Benign = movable
1) not attached
2) not invasive
b. Malignant = attached
1)May grow into bone

42. Symptoms & Signs, continued …
7. Consistency of mass
a. Cysts = fluctuant; compressible
b. Fibroadenoma = rubbery
c. Carcinoma = firm, hard (like gravel)
8. Axillary area lymph node enlargement

43. D. Benign breast conditions
1. Infection = usually during or after
lactation
a. Recurrent, subareolar abscess
b. TB of the breast
2. Trauma = contusion
3. Hypertrophy = seen in either sex at
adolescence
a. Gynecomastia = in males

44. Hypertrophy, continued …
b.
Other causes
1) testicular or pituitary tumor
2) cirrhosis
3) hypogonadism = not enough
testosterone
4) estrogen administration for
prostate cancer

45. Benign Conditions, continued
4. Tumors & cysts
a. Fibroadenoma =
most common
benign breast
tumor

46. Tumors and Cysts, con’t…
b. Breast Cyst
1. Benign
2. May be
aspirated if
large

47. Benign conditions, continued …
c. Fibrocystic breast
changes
1) 20%+ of premenopausal
women
2) discomfort, cysts
3) treatment rarely required
4) More likely to not detect a
developing cancer

48. Tumors & cysts, continued ….
d. Intraductal papilloma
- may produce
“chocolate” or
bloody discharge from
nipple
e. Lipoma: common
- fatty tumors

49. E. Carcinoma of the breast
1. Most common malignant tumor among
women
2. 1/8 of women will develop breast cancer
a. 1/6 in Orange County
b. 1/5 in San Francisco
3. Generally no discomfort

51. Breast cancer originates in breast tissue and
Breast cancer originates in breast tissue and
arises from the ductal tissue of the breast and,
arises from the ductal tissue of the breast and,
less commonly, the lobulartissue. There are
less commonly, the lobulartissue. There are
several forms of breast cancer based, in part,
several forms of breast cancer based, in part,
on cellular and genetic characteristics,
on cellular and genetic characteristics,

52. Types of Breast Cancer
Types of Breast Cancer

59. hat is HER2-positive breast cancer?
All cells have HER2 receptors, including healthy cells and cancer cells. In HER2positive breast cancer, tumor cells have more HER2 receptors than normal. Too
much HER2 makes these cancer cells grow and divide too rapidly.
NONCANCEROUS CELL

60. What is HER2-positive breast cancer?
All cells have HER2 receptors, including healthy cells and cancer cells. In HER2-positive breast
cancer, tumor cells have more HER2 receptors than normal. Too much HER2 makes these
cancer cells grow and divide too rapidly.
HER2-POSITIVE CANCER CELL
Cancer treatments called HER2-targeted therapies have been
developed to target the HER2 receptor.
PERJETA is one of those HER2-targeted therapies.

61. Progression to Breast Cancer

62. Carcinoma of breast, continued …
4. Physical signs:
a.
b.
c.
d.
Slowly growing, painless mass
May demonstrate retracted nipple
May be bleeding from nipple
May be distorted areola, or breast
contour
e. Skin dimpling in more advanced
stages with retraction of Cooper’s
ligaments

63. Physical signs, continued …
f. Attachment of mass
g. Edema of skin
1)with “orange skin” appearance
(peau d’orange)
2) due to blocked lymphatics
h. Enlarged axillary or deep cervical
lymph nodes

64. Breast Cancer, con’t…
5. Common sites for metastasis
a. Lungs & pleura
b. Skeleton system (skull, vertebral column, pelvis)
c. Liver
6. Atypical carcinomas
a. Inflammatory carcinoma (hormonal, chemotherapy)
b. Paget’s disease of the breast