Lymphedema Pathology & Staging Flashcards

Lymphedema is defined as edema caused by which underlying mechanism?

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.

Primary lymphedema is caused by what?

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.

According to the International Society of Lymphology (ISL), Stage 0 lymphedema is characterized by what finding?

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.

In ISL Stage II lymphedema, which tissue characteristic distinguishes it from Stage I?

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.

Elephantiasis is associated with which most extreme stage of lymphedema?

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.

Filariasis-induced secondary lymphedema in the US most commonly affects which patient population?

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.