CLT Lymphedema Pathophysiology & Staging 2 — Questions and Answers
Question 1: Elephantiasis is associated with which stage of lymphedema?
- Stage 0
- Stage I
- Stage II
- Stage III (Correct answer)
Correct answer: Stage III
ISL Stage III (lymphostatic elephantiasis) features massive limb enlargement with skin changes including papillomas, lobules, and acanthosis.
Question 2: The most common cause of secondary lymphedema worldwide is:
- Cancer surgery and radiation
- Trauma and infection
- Filariasis (parasitic infection) (Correct answer)
- Chronic venous insufficiency
Correct answer: Filariasis (parasitic infection)
Lymphatic filariasis caused by Wuchereria bancrofti is the most common cause of secondary lymphedema globally, though cancer treatment is the leading cause in the US.
Question 3: What is the 'safety valve' of the lymphatic system?
- The thoracic duct valve
- The lymphatic system's reserve capacity to handle excess fluid beyond normal load (Correct answer)
- Lymph node filtration of pathogens
- The venous angle junction with the subclavian vein
Correct answer: The lymphatic system's reserve capacity to handle excess fluid beyond normal load
The safety valve refers to the lymphatic system's ability to increase flow by 10–20 times above baseline when interstitial fluid accumulates.
Question 4: Dynamic insufficiency of the lymphatic system means:
- The lymphatic transport capacity is normal but the lymphatic load is too high (Correct answer)
- The transport capacity is reduced but the load is normal
- Both capacity and load are abnormal
- Lymphatic vessels are completely obstructed
Correct answer: The lymphatic transport capacity is normal but the lymphatic load is too high
Dynamic insufficiency occurs when normal lymphatic transport capacity cannot keep up with an abnormally high lymphatic load, as in heart failure or severe hypoproteinemia.
Question 5: Mechanical insufficiency of the lymphatic system means:
- The lymphatic load is excessive
- The lymphatic transport capacity is reduced below the normal load level (Correct answer)
- Blood pressure exceeds lymphatic pressure
- Lymphangions are contracting too rapidly
Correct answer: The lymphatic transport capacity is reduced below the normal load level
Mechanical insufficiency occurs when lymphatic transport capacity is reduced (e.g., by node removal) so it can no longer handle even a normal lymphatic load.
Question 6: Lymphorrhea is defined as:
- Inflammation of lymph nodes
- Leakage of lymph fluid through the skin surface (Correct answer)
- Increased lymph node size due to infection
- Reversal of lymphatic flow
Correct answer: Leakage of lymph fluid through the skin surface
Lymphorrhea is the leakage of protein-rich lymph fluid through the skin, often through blisters or wounds in severely edematous limbs.
CLT Lymphedema Pathophysiology & Staging 2
Elephantiasis is associated with which stage of lymphedema?