Disorders of lymphatic system

Question 1

What are 5 functions of the lymphatic system?

Answer 1

1) Protein and fluid haemostasis

2) Cellular drainage from tissues

3) Immune surveillance

4) Regulation of inflammation

5) Fat haemostasis

Question 2

What are 5 consequences of lymphatic failure

Answer 2

1) Lymphoedema

2) Elephantiasis skin changes

3) Infection

4) Increased risk of local malignant changes

5) Lymphoedema fluid promotes fat deposition

Question 3

What is lymphoedema and what are some of its causes

Answer 3

Swelling of any body site - when lymphatic system inadequately drains fluid from tissues

Causes:
-Cancer treatment
- Obesity, varicose veins, immobile, inflam skin disease, BP drugs, trauma
Primary lymphoedema (genetically determined weakness of lymphatics)

Question 4

What are some clinical pointers to lymphoedema?

Answer 4

• Pitting
• Causes skin thickening and hyperkeratosis (scaling)
• May improve overnight
• Diuretics have no longterm impact
• More than one attack of cellulitis occurred

Question 5

Give 2 reasons why lymphoedema happens?

Answer 5

When microvascular filtration exceeds lymph drainage because of:

1) INCREASED FILTRATION
- e.g. venous hypertension

2) IMPAIRED FLOW OF LYMPH
- e.g. abnormal development of lymphatic vessels (primary)/ interruption of lymphatic pathways (secondary)

Question 6

What is the difference between lipoedema and lymphoedema

Answer 6

Lipoedema: Fat disorder with normal feet

Lymphoedema: drainage disorder - feet swell first then swelling goes up leg

Question 7

What is primary lymphoedema?
How has it’s classification changed over time?

Question 8

What is Milroy disease?

Answer 8

• Congenital lymphoedema of lower legs
• AUTOSOMAL DOMINANT inheritance
• Large calibre veins with venous reflux confirmed on ultrasound examination
• Increased incidence of hydroceles in affected males
• Mutations in VEGFR3 kinase domains are causative

Question 9

What is Klippel-Trenaunay syndrome and some of its complications?

Answer 9

• PIK3CA mutation
• Combined capillary, venous and lymphatic malformation
• Venous varicosities
• Hypertrophy: bone or soft tissue

Complications:
- Throbosis
- Bleeding
- Symptomatic varicose veins
- Cellulitis
- Psychological
- Secondary skeletal impacts

Question 10

Describe 3 features each of lymphoedema Distichiasis and Emberger syndrome and which gene mutation causes it

Answer 10

Lymphoedema Distichiasis (FOXC2 mutation)
- Pubertal onset of lower limb lynmphoedema
-Ptosis, cleft palate, congenital heart disease, scoliosis
- Autosomal dominant inheritance

Emberger syndrome (GATA2 mutation)
- Late onset lymphoedema of lower limbs
- Genital lymphoedema
- Autosomal dominant inheritance
- Sensorineural hearing loss, cutaneous warts

Question 10

What is Trametinib?

Answer 10

MEK Kinase inhibitors