Congestive heart failure
Deep venous thrombosis
Ans.D. Lymphatic obstruction
The patient has filarial worm infestation of an inguinal lymph node which has caused elephantiasis.
Under normal circumstances, more fluid is filtered into the interstitial spaces than is reabsorbed into the vascular bed. This excess interstitial fluid is removed by the lymphatics. Thus, obstruction to the lymphatic flow leads to localized edema formation.
Lymphatic channels can be obstructed by (1) malignant neoplasms, (2) fibrosis resulting from inflammation or irradiation, and (3) surgical ablation.
The inflammatory response to filarial worms (Bancroftian and Malayan filariasis) can result in lymphatic obstruction that produces massive lymphedema of the scrotum or extremity (elephantiasis).
Lymphatic edema differs from other forms of edema in its high protein content since lymph is the vehicle by which proteins and interstitial cells are returned to the circulation. This increased protein concentration may be a fibrogenic stimulus in the formation of dermal fibrosis in chronic edema (indurated edema). Congestive heart failure, kidney disease, and liver disease can cause generalized noninflammatory edema, but the swelling is bilateral. Although deep venous thrombosis can cause tenderness and swelling, it does not cause elephantiasis.