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

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

5. Breast Anatomy

6. 6. Fixed to skin & underlying fascia by fibrous C.T. bands
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. 6. Left breast is usually slightly larger
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. 1. Outer surface convex, skin covered 2. Nipple:
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. c. Surrounded by areola: pigmented ring of skin
Structure, continued …
c. Surrounded by areola: pigmented ring of skin
d. Thin skinned region lacking hair, sweat glands
e. Contains areolar glands

13. a. Circular and radial smooth muscle fibers
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. a. Each lobe has one lactiferous duct
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. a. Form ampullae (collection sites of lactiferous sinuses)
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. a. Changes with hormonal signals b. Onset of menstruation
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. b. Passes under axillary fascia
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. a. Determines form & size of breast
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. 1. Arteries: derived from thoracic branches of three pairs of arteries
Structure, continued …
Vessels & nerves
1. Arteries: derived from thoracic branches of three pairs of arteries
a. Axillary arteries
1) continuous with subclavian a ) gives rise to external mammary ( = lateral thoracic) artery

25. c. Intercostal arteries:
Vessels & Nerves, continued …
b. Internal mammary (thoracic) arteries ) first descending branch of subclavian artery ) 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.
Internal mammary (thoracic) a.
4. Vascular Supply to Breast (39)
External mammary (thoracic) a.

27. Vessels & Nerves, continued …
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. a. anterior & lateral cutaneous nerves of thorax
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
Parasternal nodes
Lateral pectoral nodes

32. c. Superficial regions of skin, areola, nipples:
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
6. Lymph Vessels of Mammary Glands (41)
Subdiaphragmatic Lymph Channels

36. 1. Inverted nipple: congenital or due to cancer 2. Ectopic nipple:
Structure, continued …
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. a. breast development of male in areolar region
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. a. Menstruation – tenderness from fluid engorgement
Diseases of the breast, continued …
3. Endocrine influence
a. Menstruation – tenderness from fluid engorgement
b. Post-menopause ) decrease of fibro-cystic disease ) increase in cancer
c. Pregnancy

40. C. General symptoms & signs 1. Nipple discharge
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. 5. Retraction sign: “dimpling” involving skin, nipple or areola
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. a. Cysts = fluctuant; compressible
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. b. Other causes 1) testicular or pituitary tumor 2) cirrhosis
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. c. Fibrocystic breast changes
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. d. Intraductal papilloma
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
Most common malignant tumor among women
1/8 of women will develop breast cancer
a. 1/6 in Orange County
b. 1/5 in San Francisco
3. Generally no discomfort

50. Progression to Breast Cancer

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

52. f. Attachment of mass g. Edema of skin
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

53. 5. Common sites for metastasis
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