1. Thorax
Breasts

2. Breasts

3. Breast Modified sweat glands
Glandular tissue embedded within superficial fascia of anterior chest wall
Modified sweat glands
Overlying pectoral muscles
Rudimentary in males and pre-pubertal females
Size and shape of adult female breast varies
Determined by amount of fat surrounding glandular tissue

4. Extent-
Base
Extending from lateral border of sternum to midaxillary line and from 2nd to 6th ribs.
Majority of breast overlies deep pectoral fascia of pec major muscle, with remainder overlying fascia of serratus anterior
Retromammary space
A potential space filled with loose connective tissue
Breast is separated from pectoralis major muscle
Axillary tail (of Spence)
A small part of mammary gland extend toward axilla

6. Axillary tail (of Spence)

7. Structure of Breast Areola Surrounds the nipple
Circular pigmented area of skin
Breast composed of 15 to 20 lobules of glandular tissue
Formed by septa of suspensory ligaments
Each lobule is drained by a lactiferous duct
Each lactiferous duct opens on nipple
Firmly attached to overlying skin by
Suspensory ligaments (of Cooper)

8. Nipple location
4th intercostal space

9. Cooper’s Suspensory Ligaments

10. Vasculature of Breast Arterial supply
Anterior intercostal A. (from internal thoracic artery)
Lateral thoracic A. (from axillary artery)
Posterior intercostal A.
Branch of thoracic aorta 2nd, 3rd, & 4th P.I.C.

11. Arterial Supply to the Breast

12. Lateral thoracic drain into Axillary vein (main)
Venous drainage-
Lateral thoracic drain into Axillary vein (main)
Anterior intercostal drain into Internal thoracic vein
Posterior intercostal drain into Azygous vein

13. Veins of mammary gland

14. NERVE Supply of breast From T4-T6 nerves [somatic nerves]
(anterior and lateral branches) sensory fibers to skin
Sympathetic to :
Smooth muscle: in dermis of areola and nipple
Blood vessels

15. Lymphatic Drainage of Breast
Lymph from nipple, areola, and lobules of mammary glands- subareolar lymphatic plexus
From there, a system of interconnecting lymphatic channels drains lymph to various lymph nodes
Majority (75%) of lymph, especially from lateral quadrants→ pectoral nodes→ axillary nodes
Remaining lymph, especially from medial quadrants→ parasternal lymph nodes along internal thoracic vessels

16. Breast Quadrants

17. Lymphatic drainage of breast

18. Some lymph from lower quadrants→ inferior phrenic nodes
Lymph from medial quadrants can cross to opposite breast via parasternal nodes
Secondary metastases of breast carcinoma can spread to opposite breast in this way

19. Major Routes of Metastasis
Channels to Contralateral Breast
Axillary Lymph Channels
6. Lymph Vessels of Mammary Glands (41)
Subdiaphragmatic Lymph Channels

21. Examination of Breast Clinically breast is divided into quadrants:
UI: upper inner
UO: upper outer (includes axillary tail)
LI: lower inner
LO: lower outer
Breast palpation-
Circular fashion, beginning with nipple and moving outward
Palpation should extend into axilla to palpate axillary tails
After palpation of one breast, other should be palpated in same way
Examine skin of breast for a change in texture or dimpling (peau d'orange sign) and nipple for retraction→ these signs indicate an underlying pathology

24. Breast self exam

25. Mammography Mammography is a radiographic examination of the breast
This technique is extensively used for screening the breasts for benign and malignant tumors and cysts.
Extremely low doses of x-rays are used so that the dangers are minimal and the examination can be repeated often.
Its success is based on the fact that a lesion measuring only a few millimeters in diameter can be detected long before it is felt by clinical examination.

27. Carcinoma of the Breast
Approximately 60% of carcinomas of the breast occur in the upper lateral quadrant.
The cancer cells are swept along the lymph vessels and follow the lymph stream. The entrance of cancer cells into the blood vessels accounts for the metastases in distant bones.
The lymphatic spread of cancer to the opposite breast, to the abdominal cavity, or into lymph nodes in the root of the neck is caused by obstruction of the normal lymphatic pathways by malignant cells or destruction of lymph vessels by surgery or radiotherapy.

28. Peau d’orange sign Leathery thickening of the skin
Often dimpled and has prominent pores
That gives the skin the appearance of orange peel
The dimples and the pores results from shortening of the suspensory ligament Because of cancerous invasion

29. Peau d’orange sign:

30. Carcinoma of the Breast

31. Mastectomy
A simple mastectomy in which the pectoral muscles are left intact. The axillary lymph nodes, fat, and fascia are removed.
Radical mastectomy is designed to remove the primary tumor and the lymph vessels and nodes that drain the area.

32. Mastectomy

33. Radical mastectomy