CLT Lymphedema Pathology & Staging 1 — Questions and Answers
Question 1: Lymphedema is defined as edema caused by which underlying mechanism?
- Increased venous pressure from heart failure
- Insufficient lymphatic transport capacity relative to lymphatic load (Correct answer)
- Decreased serum albumin from liver disease
- Excess antidiuretic hormone secretion
Correct answer: Insufficient lymphatic transport capacity relative to lymphatic load
Lymphedema results when the lymphatic system's transport capacity is overwhelmed or reduced, causing protein-rich fluid to accumulate in interstitial spaces.
Question 2: Primary lymphedema is caused by what?
- Removal of lymph nodes during cancer surgery
- Congenital or developmental abnormalities of lymphatic vessels or nodes (Correct answer)
- Infection by Wuchereria bancrofti
- Trauma to lymphatic vessels
Correct answer: Congenital or developmental abnormalities of lymphatic vessels or nodes
Primary lymphedema arises from intrinsic developmental anomalies such as aplasia, hypoplasia, or hyperplasia of lymphatic structures.
Question 3: According to the International Society of Lymphology (ISL), Stage 0 lymphedema is characterized by what finding?
- Visible, non-pitting edema present at rest
- Latent or subclinical condition where transport is impaired but swelling is not yet present (Correct answer)
- Fibrotic, irreversible tissue changes
- Pitting edema that reverses with elevation
Correct answer: Latent or subclinical condition where transport is impaired but swelling is not yet present
ISL Stage 0 (subclinical) describes impaired lymph transport without visible swelling — patients may report heaviness but volume is still normal.
Question 4: In ISL Stage II lymphedema, which tissue characteristic distinguishes it from Stage I?
- The edema pits easily
- Spontaneous reversibility with limb elevation
- Fibrotic tissue changes; pitting may or may not be present and elevation alone does not reverse swelling (Correct answer)
- No swelling is visible
Correct answer: Fibrotic tissue changes; pitting may or may not be present and elevation alone does not reverse swelling
Stage II lymphedema involves early fibrosis and connective tissue changes, so the swelling no longer reverses with elevation alone, and pitting becomes variable.
Question 5: Elephantiasis is associated with which most extreme stage of lymphedema?
- ISL Stage 0
- ISL Stage I
- ISL Stage II
- ISL Stage III (Correct answer)
Correct answer: ISL Stage III
ISL Stage III (lymphostatic elephantiasis) involves massive swelling with severe skin changes, fibrosis, acanthosis, and fat deposition that give the limb a grossly distorted appearance.
Question 6: Filariasis-induced secondary lymphedema in the US most commonly affects which patient population?
- Elderly women post-mastectomy
- Immigrants from tropical regions where Wuchereria bancrofti is endemic (Correct answer)
- Athletes with repetitive limb injuries
- Post-surgical knee replacement patients
Correct answer: Immigrants from tropical regions where Wuchereria bancrofti is endemic
Filariasis is the world's leading cause of secondary lymphedema globally but in the US it primarily affects immigrants from tropical endemic regions.
CLT Lymphedema Pathology & Staging 1
Lymphedema is defined as edema caused by which underlying mechanism?