Breast oncology

1. BREAST CANCER
RELEVANT ANATOMY
DR SURANJAN MAITRA

2. INTRODUCTION
• Modified sweat
gland, tubulo-alveolar
gland
• Composed of adipose
tissue, lactiferous
ducts & tubules,
blood vessels, nerves
and lymphatics

3. Contd…
• Secondary reproductive organ
• Primary action – milk production to nourish
offspring
• Secretory units – alveoli
• Developes at puberty in females
• Undergoes several physiological changes
throughout the life
• Controlled by different hormones
• Rudimentary in males

4. LOCATION
• Extends from:
superiorly 2nd rib to
inferiorly 6th rib and
medially from Lateral
border of sternum to
mid-axillary line
laterally

5. Contd… Axillary Tail
Named after a Scottish surgeon James Spence (1812-1882)

6. Deep Relations
• As an ectodermal derivative, the gland lies
in a pocket of superficial fascia.
• Superficial fascia:
– Superficial layer
– Deep layer
• The deep layer of the superficial fascia is
thicker.

7. Contd…
• Beneath this sheath is a
layer of filmy areolar tissue
that allows the breast to
move freely on the
underlying fascial covering of
the pectoralis major and the
serratus anterior.(Pectoralis
fascia)
• This areolar layer forms the
retromammary space/
Submammary space.
• Deep infiltration of a cancer
through this space into the
underlying pectoralis fascia
produces the physical sign of
deep tethering of a
malignant breast mass.

8. STRUCTURE
• Skin – nipple, areola
• Parenchyma
• Stroma

9. Nipple-Areolar Complex
• Nipple is a conical
projection covered by
thickened skin
• Lies at the level of 4th
inter costal space
• Areola is pigmented
circular area around
base of the nipple
• Montgomery
tubercles are
modified sebaceous
glands

10. Breast Parenchyma
Lobes
• 15-20 in number
• Composed of minute glandular
structures called lobules
• Lobules empty via ductules in
lactiferous ducts
Lactiferous Ducts
• Open at nipple
• Ampulla/lactiferous sinus near its end
(Reservoir of milk or abnormal
discharge)

12. Stroma
• Supporting framework of
the gland
• Partly fibrous and partly
fatty tissue
• Condensed fibrous tissue
forming septa are known as
suspensory ligament of
Cooper which anchor the
superficial fascia to the
deep fascia
• Fatty tissue forms the
hemispherical contour of
the breast

13. Areterial Supply
• Arterial supply from
Perforating branches of Int. Mammary artery
Lateral branches of Post. Inter costal arteries
Branches of Axillary artery – superior
thoracic, lateral thoracic, thoraco acromial
(pectoral branches)

15. Venous Drainage
• Veins follow the arteries
• First converge around nipple to form an
anastomotic venous circle & then form 2 sets
of veins:
Superficial veins: drain internal thoracic vein
and superficial neck veins
Deep veins: drain to internal thoracic, axillary
& posterior intercostal veins

17. Nerve supply
• 4th to 6th intercostal nerves by their Anterior
and Lateral cutaneous branches

18. Lymphatic drainage
• This is of considerable importance in the
spread of malignant breast tumours.
• The lymph drainage of the breast, as with any
other organ, follows the pathway of its blood
supply and therefore travels:
– along tributaries of the axillary vessels to axillary
lymph nodes;
– along the tributaries of the internal thoracic
vessels to the internal mammary chain
– Along the intercostal vessels.

19. Contd…
• there is a tendency
for the lateral part of
the breast to drain
towards the axilla and
the medial part to the
internal mammary
chain
• Four inter -
communicating
lymphatic plexi –two
superficial & two
deep

20. Contd…
 Superficial Plexi – Cutaneous and Subcutaneous
 Deep Plexi – Fascial and Glandular
 Glandular plexus communicates with sub
areolar plexus of Sappey
 Breast lymphatics may also drain to lymphatic
plexus of liver and sub diaphragmatic plexus -
path of Gerota

21. Contd…
• Predominant drainage of breast lymphatics is
to Axillary nodes
• May also drain directly to Int.Mammary nodes
• Occasionally, may follow cutaneous branches
of inter costal vessels towards Posterior
Inter costal nodes
• Superficial lymph vessels located more
cranially in the breast may continue to the
Supra clavicular nodes

22. Axillary Lymph Nodes
• Pectoral
• Sub scapular
• Lateral
• Central
• Apical

23. • Efferents from apical
group – Subclavian
lymph trunk – Jugular
lymph trunk & Broncho
mediastinal lymph
trunk – Right
lymphatic duct /
Thoracic duct

24. Other Lymph Nodes of Importance
• Internal Mammary – located on either side of
sternum – 1st to 3rd and 5th to 6th inter costal
spaces – drain to broncho mediastinal lymph
trunk
• Inter pectoral (Rotter’s) – 1-4 small nodes
located between the pectoralis major and
minor – drain to central or rarely to apical
• Delto pectoral – 1-2 nodes located in delto
pectoral groove – drain to central and apical
group and rarely to lower deep cervical nodes

25. Levels of Axillary Nodes
• Level I – located
laterally or below the
lower margin of
pectoralis minor
• Level II – located
deeply in relation to
pectoralis minor
• Level III – located
medially or superiorly
to upper margin of
pectoralis minor

26. Surgical Importance
• Simple Mastectomy
• Extended Simple Mastectomy – Level I nodes
• Modified Radical Mastectomy ( Madden) –
Levels I+II nodes
• Patey’s Modification of Radical Mastectomy –
removes pectoralis minor to allow complete
dissection of Level III nodes besides I+II
• Radical Mastectomy (Halsted) – removes
pectoralis major and minor along with Levels
I, II, & III nodes

27. Incidence of Metastatic Axillary Lymph Nodes in
Carcinoma Breast Co-related with Tumour Size
Study <0.5 0.6-1 1.0-2 2.1-3 3.1-5
Washington U. 5% 12% 20% 34% 29%
Tinnemans et
al.
7.7% 12.5% 29.5% - -
Silverstein et
al.
3% 17% 32% 44% -

28. Lymphatic spread
• Lymphatic spread of a growth of the breast may occur
further afield when these normal pathways have
become interrupted by malignant deposits, surgery or
radiotherapy.
• Secondaries may then be found in the
– lymphatics of the opposite breast or in the opposite
axillary lymph nodes
– the groin lymph nodes (via lymph vessels in the trunk wall)
– the cervical nodes (as a result of retrograde extension
from the blocked thoracic duct or jugular trunk
– in peritoneal lymphatics spreading there in a retrograde
manner from the lower internal mammary nodes

29. Patterns of Lymph Drainage

30. Incidence of Carcinoma Breast From
Different Quadrants of Breast
• Upper Outer 38.5%
• Central 29%
• Upper Inner 14.2%
• Lower Outer 8.8%
• Lower Inner 5%

31. Sentinel Lymph Node Biopsy
• A sentinel lymph node
is the first lymph
node(s) to which cancer
cells are likely to spread
from the primary
tumour
• SLN biopsy can be used
to help determine the
extent or stage of
cancer