1. The document discusses the anatomical basis for the spread of breast cancer. It describes the surgical boundaries of the breast and details the lymphatic drainage pathways from the breast to axillary and parasternal lymph nodes. 2. The main routes of spread of breast cancer are through lymphatic vessels to axillary lymph nodes and through the bloodstream to distant organs via the internal mammary veins which connect to Batson's vertebral venous plexus. 3. Understanding the lymphatic drainage of the breast is important for staging of breast cancer and determining the appropriate surgical approach and extent of lymph node dissection.

1. Anatomical Basis of Spread of
Breast Cancer
Dr.K.V.Madhusudhan
Assistant Professor
Dept of General surgery
Govt Medical College
Anantapur

2. "We realise the importance of highlighting awareness around breast
cancer and for us to play in pink is our way of contributing to the
campaign".

3. Surgical AnatomyBreast
Glandular tissue -Mammary Gland
(accessory female reproductive tissue)
Parenchyma
(Functional component)
15-20 lactiferous ducts 
Ductules  lobules
Stroma
(structural/supportive
component)
Subcutaneous tissue (fat)

4. Surgical Anatomy
Mammary glands are modified sweat glands
Therefore they have no special capsule or sheath
Protuberant conical form with roughly circular base of cone having diameter
of 10-12 cm

5. Surgical Anatomy
Gross anatomy boundaries:
Second/third rib to inframammary fold (sixth/seventh rib)
Lateral border of sternum to anterior or mid axillary line
Surgical Boundaries:
Clavicle above to 7th or 8th ribs below
Midline to the edge of latissimus dorsi posteriorly (post axillary line)
Significance:
During mastectomy, whole of tissue breast(i.e. surgical boundaries) MUST beexcised.

6. Surgical Anatomy

7. Surgical Anatomy
Breast bed (posterior/deep surface)
2/3rd formed by pectoral fascia overlying the pectoralis major
Rest by fascia overlying the serratus anterior
Inferiorly, overlying external oblique and upper extent of rectus sheath
Between investing fascia of breast and pectoral fascia is a loose connective tissue plane
or potential space - retro mammary space (bursa)
Significance:
This plane containing a small amount of fat allows the breast some degree of movement on
pectoral fascia and
This is plane of dissection during mastectomy

8. Surgical Anatomy
Significance –Retromammary space/bursa
Breast elevates when pectoralis major contracts (sign of advanced cancer) if cancer cells spread
deeply directly to invade
Retromammary space
Deep pectoral fascia overlying pectoralis major,
or metastasis to interpectoral(rotter’s) nodes.
Patient places her hands on her hips and press while pulling her elbows forward to tense her pectoral
muscles

9. Surgical Anatomy
Axillary process or tail (of Spence):
Small part of mammary gland may extend along the inferolateral edge of pectoralis
major toward the axillary fossa (armpit)
Significance:
In some normal subjects it is palpable and in a few, it can be seen premenstrually or
during lactation
If well-developed, sometimes mistaken for a mass of enlarged lymph nodes or a lipoma or
lump(tumor)
James Spence
(1812-1882)
Scottish surgeon
* Upper outer quadrant contains greater volume of tissue than othersquadrants
(hence most common site of carcinoma)

10. Surgical Anatomy
Suspensory ligaments (of Cooper-1840):
Hollow conical projections of condensed fibrous connective tissue filled with breast
tissue
Apices of the cones are attached firmly to the superficial fascia and thereby to the
dermis of skin overlying the breast
Significance:
Well developed in superior part of breast help support the mammary glandlobules
Account for the dimpling of the skin overlying a carcinoma (get shorten due to infiltration
of malignant cells)
Sir Astley Paston Cooper
(1768-1841)
British Surgeon

11. Surgical Anatomy
Lobule:
Basic structural unit of mammary gland
Number and size vary enormously (most numerous in young women)
From 10 to > 100 lobules empty via ductules into lactiferous duct, of which there
are 15 – 20, usually opens independently on the nipple.(Each duct represents one
lobe of breast)
Each lactiferous duct is lined with a spiral arrangement of contractile
myoepithelial cells
Deep to areola each duct has a terminal ampulla – lactiferous sinus, a reservoir for
milk or abnormal discharges. Involved in let-down reflex.
Ducts converge toward the nipple like the spokes of bicycle wheel

12. Surgical Anatomy
Areola (L. small area)
Circular pigmented area of skin surrounding the nipple
Epithelium contains numerous sweat glands and sebaceous glands, latter
enlarge during pregnancy and serve to lubricate the nipple during lactation
(Areolar glands or glands of Montgomery)
portions of the gland visible on the skin's surface are called "Montgomery
tubercles". (1837)
Contains involuntary muscle arranged in concentric rings as well as radially in
subcutaneous layer
William Fetherstone Montgomery
( 1797 – 1859)
Irish Obstetrician

13. Surgical Anatomy
Nipple (derived from old English word neb, meaning face/nose/beak)
Conical or cylindrical prominences in the centers of the areola
Thick skin with corrugations i.e.
No fat, hair or sweat glands
Near its apex lie orifices of lactiferous ducts
Contains smooth muscle fibers arranged concentrically and longitudinally;
thus it is an erectile structure, which points outwards.

14. Route of Spread of Malignant tumorsTumor
Bengin
Malignant
(cancer)
Epithelium
(parenchyma)
Carcinoma Lymphatic spread
Connective tissue
(stroma)
Sarcoma
Hematogenous
spread

15. Axilla

16. Axilla
Apex Outer border of 1st rib, sup border of scapula, post border of clavicle
Floor Skin (visible part of axilla)
Medial Serratus anterior, ribcage
Lateral Intertubercular sulcus of humerus
Anterior Pectoralis major & minor
Posterior Subscapularis(above), Latissimus dorsi & teres major (below)

17. Axillary Lymph nodes
Level
(with respect to
pectoralis minor)
Group Relation to Axillary
fossa
Number of
nodes
Relation to adjacent structure Drainage area
Level I Lymph nodes
(lateral or below the
lower border of
Pectoralis minor)
Axillary vein group
(Humeral group)
Lateral group 4-6 Medial or posterior to axillary vein Upper extremity
External mammary
group
Anterior or pectoral
group
5-6 Along lower border of pectoralis minor
Contiguous with lateral thoracic vessels
Lateral aspect of breast
Scapular group Posterior or
subscapular group
5-7 Along posterior wall axilla at lateral borderof
scapula
Contiguous with subscapular vessels
Lower posterior neck
Posterior trunk
Posterior shoulder
Level II Lymph nodes
(superficial or deep
to pectoralis minor)
Central group 3-4 sets Embedded in fat
Immediately posterior to pectoralis minor
Above 3 groups
Directly from breast
Interpectoral group
(Rotter’s Lymph
nodes)
1-4 Interposed between pectoralis major and
pectoralis minor
Directly from breast
Level III Lymph nodes
(medial or above the
upper border of
pectoralis minor)
Subclavicular group Apical group 6-12 sets Posterior and superior to upper border of
pectoralis minor
All other groups of axillary
lymph nodes
Josef Rotter (1857-1924)
German surgeon

18. Axillary Lymph nodes

19. Axillary Lymph nodes
Axillary nodes  clavicular (infra and supraclavicular) lymph nodes 
subclavian lymphatic trunk (drains upper limb)
Parasternal lymph nodes  bronchomediastinal trunk (drains thoracic viscera)
Venous angle
(Junction of internal jugular
and subclavian vein)

20. Axillary Lymph nodes

22. Parasternal (internal mammary) lymph
nodes
Afferent:
Lymph vessels that accompany the perforating branches of the internal mammary
artery enters into parasternal (internal mammary) group of lymph nodes
Site:
Lie along the internal mammary vessels dep to plane of costal cartilages
Drain posterior 1/3rd of the breast
Not routinely dissected although they were once biopsied for staging.
Efferent:
Drains into bronchomediastinal lymphatic trunk (draining thoracic viscera)

23. Lymphatic Drainage

24. Lymphatic DrainageNipple,Areola&Lobules
(Lymphaticplexuses–interlobularconnective
tissueandwallsoflactiferousducts)
Subareolar lmyphatic
plexus
Intially to anterior or pectoral nodes for most part
Some lymph drain directly to other axillary
nodes (post, central, apical-upper part)
Interpectoral
> 75(~85) % (especially
from lateral half) drains
to axillary lymph nodes
Deltopectoral
Supraclavicular
Inferior dep cervical
nodes
Most of rest (esp Medial
half) - parasternal
lymph nodes
Opposite breast
Subdiapharmatic inferior
phrenic lymph
nodes(inferior half)
abdomen

25. Lymphatic Drainage
Skin (excluding
nipple and
areola)
Ipsilateral
axillary
Inferior deep
cervical
Infraclavicular
Bilateral Parasternal

26. Sentinel node
Defined as 1st lymph node draining the tumor-bearing area of the breast.
Absence of enlarged axillary lymph nodes is no guarantee that metastasis
from breast cancer has not occurred because malignant cells may have passed
to other nodes, such as infraclavicular and supraclavicular lymph nodes.
Directly.

27. Peau d’orange
Due to blockage of subareolar lymphatic plexus by metastatic cells (lymphedema)
In turn causes deviation of nipple and thickened leather-like appearance of skin
Prominent or puffy skin between dimpled pores  orange –peel appearance (peau d’orange
sign)
Larger dimples (fingertip size or bigger) due to cancerous invasion of glandular tissue and
fibrosis (fibrous degeneration), causing shortening, places traction on suspensory
ligaments.
Subareaolar breast cancer may cause inversion of nipple by similar mechanism involving
lactiferous ducts

28. Arterial supply
Medial mammary arteries/ branches of
perforating branches and
2nd 3rd and 4th anterior intercostal branches of the internal thoracic/mammary artery
(origin: subclavian artery)
(origin: 2nd part of axillary artery)
Lateral mammary branches of
Highest thoracic
Lateral thoracic artery
Pectoral branches of thoracoacromial artery
lateral cutaneous branches of posterior intercostal arteries (origin: thoracic aorta) in 2nd, 3rd
and 4th intercostal spaces.

29. Arterial Supply

30. Venous drainage
3 Principal groups of veins
1. Perforating branches of internal thoracic
vein
2. Perforating branches of posterior
intercostal veins
3. Tributaries of the axillary vein

31. Batson’s (1940) vertebral venous plexus
A network of valve less veins in the human body that connect the
deep pelvic veins and thoracic veins (draining the inferior end of the urinary
bladder, breast and prostate) to the internal vertebral venous plexuses
Invests the vertebrae and extends from the base of the skull to the sacrum
Posterior intercostal veins azygous/hemiazygous system of veins alongside
bodies of vertebrae Batson vertebral venous plexus  internal vertebral
venous plexus surrounding the spinal cord
May provide a route for breast cancer metastases to vertebrae, skull, pelvic
bones and CNS.
Oscar Vivian Batson
(1894-1979)
Anatomist

32. Spread to overlying skin

33. Available at surgicalpresentations