Anatomical basis of Spread of Breast

CarcinomaJibran Mohsin

Resident, Surgical Unit ISIMS/Services Hospital, Lahore

Surgical AnatomyBr

east

Glandular tissue -Mammary Gland (accessory female reproductive

tissue)

Parenchyma(Functional component)

15-20 lactiferous ducts Ductules lobules

Stroma(structural/supportive

component)Subcutaneous tissue (fat)

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

Surgical Anatomy

Gross anatomy boundaries: Second/third 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 be

excised.

Surgical Anatomy

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

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 he elbows forward to tense her pectoral muscles

Surgical Anatomy

Axillary process or tail (of Spence): Small part of mammary gland may extend along the inferolateral edge of

posterior 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 others quadrants (hence most common site of carcinoma)

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 gland

lobules 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

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

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

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.

Route of Spread of Malignant tumors

Tum

or Bengin

Malignant(cancer)

Epithelium(parenchyma) Carcinoma Lymphatic

spreadConnective

tissue(stroma)

Sarcoma Hematogenous spread

Axilla

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)

Axillary Lymph nodesLevel(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 minorContiguous with lateral thoracic vessels

Lateral aspect of breast

Scapular group Posterior or subscapular group

5-7 Along posterior wall axilla at lateral border of scapulaContiguous with subscapular vessels

Lower posterior neckPosterior trunkPosterior shoulder

Level II Lymph nodes(superficial or deep to pectoralis minor)

Central group 3-4 sets Embedded in fatImmediately posterior to pectoralis minor

Above 3 groupsDirectly 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

Axillary Lymph nodes

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)

Axillary Lymph nodes

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)

Lymphatic Drainage

Lymphatic DrainageNi

pple

, Are

ola

& Lo

bule

s (L

ymph

atic

plex

uses

– in

terlo

bula

r co

nnec

tive

tissu

e an

d wa

lls o

f lac

tifer

ous

duct

s) Subareolar lmyphatic plexus

> 75(~85) % (especially from lateral half) drains to axillary

lymph nodes

Intially to anterior or pectoral nodes for most part

Some lymph drain directly to other axillary nodes (post, central, apical-

upper part)

Interpectoral

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

Lymphatic Drainage

Skin (excluding nipple and

areola)

Ipsilateral

axillary

Inferior deep cervical

Infraclavicular

Bilateral Parasternal

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.

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

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)

Lateral mammary branches of Highest thoracic Lateral thoracic artery (origin: 2nd part of axillary artery) Pectoral branches of thoracoacromial artery lateral cutaneous branches of posterior intercostal arteries (origin: thoracic aorta) in

2nd, 3rd and 4th intercostal spaces.

Arterial Supply

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

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

Spread to overlying skin

Available at surgicalpresentations