83. Disorders of lymphatic vessels.

Question 1

Intro to disorders + Lymphangitis

Answer 1

Intro: primary disorders extremely uncommon, usually due to inflammatory, infectious, or malignant processes secondarily

definition: acute inflammation caused by bacteria seeding in lymphatic vessels

associated with acute lymphadenitis (enlargement of draining lymph nodes) and bacteremia

Question 2

Lymphedema (definition)

Answer 2

definition: edema caused by obstruction of lymphatic system

types: 
primary lymphedema (congenital)
secondary lymphedema (acquired)

Question 3

Primary lymphedema (congenital)

Answer 3

1. simple congenital lymphedema (non-familial, no known etiology)
2. Milory disease (also known as heredofamilial congenital lymphedema)
   • autosomal dominant congenital abnormalties in
     lymph drainage system
   • agenesis or hypoplasia of lymphatics
   • mutation in VEGFR-3 which is a major receptor for
     lymphatic development

Question 4

Secondary lymphedema (acquired)

Answer 4

1. tumor
2. surgical procedures that alter lymphatic connection (ex: axillary lymph nodes in mastectomy)
3. radiation –> post-radiation fibrosis
4. Filariasis: parasite roundworm infection that cause fibrosis of lymph causing obstruction
5. Post-inflammatory thrombosis and scarring