Lymphatic Drainage of the breast Flashcards
What are the mammary glands
A modified (apocrine) sweat gland, and under hormonal influence to produce milk post-partum, it is made up of glandular tissue, fat and fibrous tissue
Found in the superficial fascia
Anterior to the pectoral muscles and the anterior thoracic wall
What do the breasts consist of
Mammary glands and associated skin and connective tissues.
Describe the embryology of the breast
The human breast develops under genetic and hormonal influence from skin precursor cells (ectoderm) during the fourth week of embryonic life.
Mammary ridges evolve in humans on the chest at the level of the fourth intercostal space and form a mammary bud by the fifth week of gestation
Background breast stroma (fat, ligaments, nerves, arteries, veins, and lymphatics) develops through- out gestation.
Beyond the twelfth week of gestation, the secondary buds continue to lengthen and branch, forming a complex network of radially arranged breast ducts that connect the developing (inverted) nipple with the growing mammary lobules
Failure of nipple eversion can occur, is often hereditary, and is usually secondary to fibrous tethering of the nipple within a hypoplastic ductal system.
After cessation of maternal hormone effects after birth, the breasts become quiescent until the onset of puberty.
What are the key events in the embryology of the breast
5th Week
Development
Mammary Bud
> 5th Week
Growth of Mammary
Bud into Chest
5-12th Week
Formation of
Secondary Buds
12th Week
Formation of
Mammary lobules
> 12th Week
Lengthening and branching
of ducts that connect the
developing (inverted) nipple
Describe nipple inversion
After gestation
Secondary to tissue attachment from back of nipple.
Describe the anatomy of the breast
Extends from the 2nd à 6th rib mid-clavicular.
o Nipple is located just inferior to 4th CC.
The breast lies on the deep fascia related to the pectoralis major muscle and other surrounding muscles.
The base extends transversely from the sternum and as far laterally as the midaxillary line
The breast parenchyma extends in the anterior axillary fold as the axillary tail of Spence
What are the areas of the breast
Body sternum
Axillary tail Anterior axillary Fold Nipple Areola Inframammary fold Intramammary Cleft (cleavage)
Which part of the breast contains the greatest volume
The upper half of the breast esp the UOQ contains the the greastest volume of breast tissue compared to the remaining breast
What does the breast consist of
The gland is comprised of 15-20 ductal-lobular units (lactiferous ducts) each draining into a main duct
Fat lies interspersed between the ductal lobular units
Divided by fibrous septae that radiate from the centre outwards (suspensory ligaments of Cooper).
There is a complex network behind the nipple and between 4 and 18 milk ducts open on the summit of the nipple or on the areola.
What happens during suckling
§ The deeper lactiferous sinuses are squeezed during suckling.
Describe the suspensory ligaments of cooper
-Connective tissue strandsthat connect anterior and posterior fascial planes
-Supporting structure
-Provides shape and consistency of parenchyma
The fibrous septae that radiate from the centre support the breast.
o Known as the suspensory ligaments of Cooper.
Describe the blood supply to the breast
Laterally- vessels from the axillary artery- superior thoracic, thoraco-acromial, lateral thoracic and supcapsular arteries
Medially- branches from the internal thoracic artery
second to fourth intercostal arteries via branches that perforate the thoracic wall and overlying muscle.
The nipple-areola receives a branch from the internal thoracic artery in most cases.
Describe the blood supply to the skin of the breast
The skin is supplied by the subdermal plexus which communicates with the deep parenchymal vessels.
Describe venous drainage of the breast
3 principle groups of veins
Perforating branches of the internal mammary vein
Tributaries of the axillary vein
Perforating branches of the posterior intercostal veins
(these lie in direct continuity with the vertebral plexus of veins (Batson plexus) – important conduit for haematogenous dissemination of breast cancer to spine or pelvis
Describe the innervation of the breast
Mainly - anterolateral and anteromedial branches of thoracic intercostal nerves T3-T6. There is also innervation from the supraclavicular nerves to the upper and lateral parts of the breast.
The nipple - dominant supply from the lateral cutaneous branch of T4.
Principally through the lateral and anterior cutaneous branches of the 2nd through 6th intercostal nerves
Describe the lymphatic drainage of the breast
Approximately 75% is via lymphatic vessels that drain laterally and superiorly into axillary nodes (humeral, pectoral, subscapular, central and apical nodes)
Some drainage into , supraclavicular or deep cervical LNs
Medial quadrant – drains Internal Mammary LNs –
- Lower quadrant – drains inferior phrenic (abdominal) nodes
Most of the remaining drainage is into parasternal nodes deep to the anterior thoracic wall and is associated with the internal thoracic artery
Some drainage may occur in the lymphatic vessels that follow the lateral branches of posterior intercostal arteries and connect with intercostal nodes situated near the head and neck of ribs.
Describe the breast as a pyramid and highlight its boundaries
A pyramidal compartment that is tightly invested between the upper extremity and the thoracic wall – 4 boundaries
- Medially: Serratus Anterior over 1st 4 ribs
Laterally: Intertubercular groove of humerus & Biceps tendon, & Coracobrachialis
Anteriorly: Pectoralis Major & Minor - Posteriorly: Teres Major, Subscapularis + tendon Latissimus Dorsi
Lymph nodes found on each corner of the breast
Where are Rotter’s lymph nodes found
Between pec major and pec minor
Describe the lymphatics of the breast
§ Lymphatics help mediate the spread of cancer.
§ Drainage from the breast is predominantly towards the axilla.
§ Removal of too many lymph nodes in the axilla result in oedema in the associated arm.
o This means usually just the sentinel node is removed (the closest node).
o Located by injecting a small volume of dye which the closest node will take up.
o This node is then removed to decrease the chance of metastasis
Describe the lymph glands of the breast
§ From the sub-mammary and sub-areolar plexuses, lymph from most of the breast drains to the:
o Pectoral group of axillary nodes (HENCE WHY MOST METASTISIS IS TO HERE).
§ There is drainage to adjacent parts of the breast too:
o Infra-clavicular group.
o Parasternal nodes.
o Mediastinal nodes.
o To the opposite breast.
Describe how we determine the severity of the breast tumour
Has the tumour grown within the breast tissue or spread to the lymph nodes
How big is it
Has the cancer spread to other organs (metastasis)
What does the tumour look like?
What receptors does it have?
Describe the lymph capillaries
Lymph capillaries make a richly anastomosing network within the breast and overlying skin.
The superficial parts of the breast drain to the sub-areolar plexus and the deep parts to the submammary plexus that lies in the deep fascia overlying pectoralis major and serratus anterior.
What are the dangers of axillary clearance surgery
Long thoracic nerves and thoracodorsal nerves are the motor nerves in the axilla- supply latissimus dorsi- may not be able to lift arm.
Describe sentinel node biopsy
Found in the axilla- can be sampled by sentinel node biopsy
Where the cancer may spread to first
Coloured dye or radioactive tracer is injected into breast tissue surrounding the tumour
The injected substance then drains into the sentinel nodes- identifying them for surgical removal
Surgically removed and examined for cancer cells
What is meant by anatomical dissection
Removal of an anatomical space
What do we use to visualise the lymph nodes
Gamma counter - Tech99- reducing morbidity of the operation
Describe breast cancer related lymph
Long term, progressive condition, poorly understood & under reported
Negatively impacts overall QoL (emotional distress, anxiety and disturbance of body image)
Risk factors:
treatment factors: axillary surgery, LRRT, systemic taxane CT
patient factors - ↑ BMI
Fiscal burden in LE patients
- $14,877 - $23,167 over 2 years
What is meant by lymphoedema
Abnormal, generalized or regional accumulation of protein rich interstitial fluid
Oedema formation and change in tissue architecture
What does lymphoedema result in
REDUCTION IN LYMPHATIC TRANSPORT CAPACITY Increased lymphatic load Also a higher risk of infection
Describe the cumulative incidence of lymphoedema
90% patients will develop LE in the first 24-36 months
What do we know about lymphoedema
Not just a blockage – “heart attack” of the lymphatic system
Long term, progressive, poorly understood & under reported
Negatively impacts overall QoL
Fat accumulation and scarring
Not all lymphoedema behaves the same way
What else can be avoided to reduce the risk of L.E
Venipuncture
Injections
BP measurements and
The use of compression sleeve for air travel
Describe the evidence for other risk factors potentially related to L.E
- Flying :It has been postulated that low cabin pressure and reduced activity may either initiate lymphedema in ‘at-risk’ patients or exacerbate the condition
Air travel has no effect on lymphoedema - Retrospective and Prospective studies have refuted this* - Blood draws andninjection - Evidence is poor quality and conflicting
Lymphoedematous limbs are prone to cellulitis after minor trauma; BUT sterile puncture of the skin does not increase infection - Hypothesis: increased pressure in the limb results in increased lymph production, fibrosis and stenosis of the lymphatic vessels
No evidence to suggest that BP readings taken from an ‘at-risk’ arm increases the risk of lymphedema - Role of exercise is controversial
Historically: avoid lifting children and heavy objects (bags)
RCTs – aerobic exercise: including yoga, nordic walking & arm cycling -SAFE
NLN emphasizes importance of exercise in both at-risk and affected patients
What are the different ways for diagnosing L.E
Self report
Water displacement therapy (strict protocol, unhygienic)
Circumferential type measurement (accessible but cumbersome and requires a lot of training to achieve reproducible results)
Perometry (expensive)
Bioimpedence spectroscopy (limited to unilateral patients, no role in established fatty lymphoedema)
List the strategies to reduce lymphoedema
Less axillary surgery
Axillary reverse mapping (ARM)
LYMPHA
Describe Axillary reverse mapping
Aims to identify and preserve nodes and/or lymphatics draining from the arm during ALND, thereby minimizing arm lymphedema
Reverse mapping – blue dye, radioisotope or ICG
How do we determine the arm nodes
ISOTOPE / ICG / DYE MAPPING
Injection into the wrist of wrist spaces of the ipsilateral arm
Site massaged and the arm elevated for 5 minutes to enhance arm lymphatic drainage
ARM localization in 90-93%
What may be the issue with Axillary reverse mapping
If there is crossover (concordance- arm lymphatic is metastatic) either:
Reanastomose the afferent and efferent lymphatics (not lumen to lumen)
LVA (LYMPHA)
What is LYMPHA
(Lymphatic Microsurgical Preventative Healing Approach
Multiple Lymphatic-venous anastomoses (LVA) between arm lymphatics and collateral branches of axillary vein at the same time as Axillary dissection
What are the benefits of LYMPHA
Short operative time
Possibly to prevent secondary lymphoedema
Reduction in early lymphatic complications
Improvement in QoL
Reduction In health costs
Describe the congenital abnormalities of the breast
Underdevelopment or absence of one breast (may coexist with muscle/ribcage anomaly) – *Poland syndrome
Accessory nipples (polythelia) absent nipples (athelia)
Accessory breast tissue
Tubular breast defomity
Describe the axillary tail of the breast
It is important for clinicians to remember when evaluating the breast for pathology that the upper lateral region can project around the lateral margin of the pectoralis major muscle and into the axilla.
This axillar process (axillary tail) may perforate deep tissue and extend as far superiorly as the apex of the axilla
What can subcutaneous lymphatic obstruction and tumour growth result in
Pulls on connective tissue ligaments in the breast, resulting in the appearance of an orange peel texture (peau d’orange) on the surface of the breast. Further subcutaneous spread can induce a rare manifestation of breast cancer that produces a hard, woody texture on the skin (cancer en cuirasse).
What are the potential complications of a mastectomy
Surgical removal of breast
Involves excision of the breast tissue to the pec major muscle and fascia
Within the axilla, the breast tissue must be removed from the medial axillary wall
Closely applied to the medial axillary wall is the long thoracic nerve
Damage to this nerve can result in paralysis of serratus anterior muscle, producing the characteristic winged scapula
It is also possible to damage the nerve to the L.dorsi and this may affect extension, medial rotation, and adduction of the humerus.
Describe the breast in men
Rudimentary and consists only of small, often composed of cords of cells, that normally do not extend beyond the areola.
Breast cancer can occur in men and also in accessory nipples.
What is the retromammary space
A layer of loose connective tissue separates the breast from the deep fascia and provides some degree of movement over underlying structures.
What does carcinoma of the breast cause
Tension on the ligaments- causing pitting of the skin.
What are the dominant components of the breast
Non lactating women= fat
Lactating women = glandular tissue
What is meant by the ligaments of cooper.
The breast is divided into fibrous septae that radiate outward (the ligaments) and sometimes the TETHERING or drawing in of the skin occurs due to the suspensory ligaments of Cooper becoming involved in the tumour process.
