Learning Objectives

At the end of the lecture, the student should be able to :

  • Describe the development of Breast.
  • Tell us the anatomy of the breast.
  • Describe Ductal System.
  • Define Stroma.
  • Tell us the arterial Supply.
  • Let know the venous drainage of breast.
  • Characterize the axillary lymph nodes.
  • Exemplify the age dependent changes.
  • Explain the physiology of breast.
  • What are fibroadenomas?
  • Describe Breast Abscess.
  • What is the importance of lymph nodes in relation with breast disease?

Lecture Outline

Development of breast:

1. Dermis.
2. Epidermis.
3. Lactiferous duct.
4. Mammary ridge.

Anatomy of the Breast:

The Breast Parenchyma:

The breast is the specialized human tissue located on the chest between the pectoralis muscle, i.e. the superficial fascia and the subcutaneous tissue, i.e. right beneath the skin.

The Retromammary Space:

The breast rests on a rich vascular and lymphatic network within the pectoralis fascia. This represents the retromammary space which is positioned between the deep pectoralis fascia and the superficial pectoralis fascia.

The Nipple-Areolar Complex:

The Nipple-Areolar complex is the center of the breast. It is the end portion of the largest lactiferous duct.

The Lobules: responsible for the production of milk.

The Ductal System: responsible for the propulsion of milk through the ductal system as it has contractile capabilities. This ductal system is sealed and surrounded by an uninterrupted basement membrane.

The Stroma: This interlobular tissue, also referred to as connective tissue, contains capillaries and other specialized cells.

Cooper's Ligaments: These are dense strands of fascia found throughout the entire breast.

The Basement Membrane of the Ductal System: It is essential to visualize the basement membrane in the microscopic analysis of a malignant breast tumor. This will assist in the assessment as to whether a tumor is "in situ".

Arterial supply:

Mainly from anterior surface, posterior surface relatively avascular

Sub clavian artery through its Internal thoracic branch ( perforating branches)

Axillary artery through its Lateral thoracic, superior thoracic and acromiothoracic branches

Posterior intercostal arteries through their lateral branches

Venous Drainage:

•Veins first converge towards the base of nipple forms anastomosing circle.

•Divides into superficial and deep sets

•Superficial drains into internal thoracic vein and superficial veins of neck.

•Deep veins into internal thoracic, axillary and posterior intercostal veins.

Axillary Lymph nodes:

A pectoral (anterior)

L lateral

P posterior

C central

Ap apical

Level I: Lymph nodes lateral and inferior to the pectoralis minor muscle .

Level II: Lymph nodes under the pectoralis minor muscle .

Level III: Lymph nodes under and deep to the pectoralis minor muscle.

Age Dependent Changes:

With age, the breast tissue will change. In a young woman, the breast tissue is dense and parenchyma rich. As the woman ages, the fat content of the breast tissue will increase. This explains the overall aspect of the breast, as it will begin to droop. The increased fat content of the breast in older patients accounts for the higher quality of their mammograms (increased fat content equals increased image quality).

Physiology of Breast

Estrogen:

Duct Elongation

Duct Branching

Inc. Fat Deposition

Progesterone

Alveolar formation

Preparation of lactation

Prolactin

Development of alveoli for secretion (during pregnancy) along with estrogen and progesterone

Milk production and release (after labour)

Pathology of breast:

Fibrocystic breast condition

Cysts - fluid-filled lumps

Fibroadenomas

Intraductal papillomas

Blocked or clogged milk ducts

Breast abscess

CA Breast

BreastCA with metastasis to axilla

What is the importance of lymph nodes in relation with breast disease???

Embryology:

The lymphatic vessels, lymphnodes, and spleen develop from lateral plate mesoderm.

The lymphatic system begins to develop by the end of the fifth week.

The lymphatic vessels may develop as an outgrowth of the venous system .

Lymph Nodes (Glands)Except for cisterna chyli, all lymphatic capillary plexuses become invaded by mesenchymal cells that proliferate and aggregate to form groups of lymph nodes.

Lymph nodes function in hematopoiesis during the medullolymphatic phase but erythropoiesis later shifts to red bone marrow. Lymph nodes primarily produce lymphocytes.

Histology of Lymph node

Areas of drainage of axillary L/N

Arms,

breast

Cervical region

Palpable axillary LN:

Infection

Local: abscess in primary areas

Breast

Upper limb

Generalized

Syphilis

Tumor

Primary: Lymphoma, CLL

Secondary: Ca Breast, Skin Cancer

Take Home Message

If there is a palpable lump in the breast its mandatory to examine the axillary lymphnodes similarly with a palpable node in axilla do a complete breast examination.