Lymphedema

Introduction

Essentials of Diagnosis

• Painless edema of upper or lower extremities.
  
• Involves the dorsal surfaces of the hands and fingers or the feet and toes.
  
• Developmental or acquired, unilateral or bilateral.
  
• Edema is pitting initially and becomes brawny and nonpitting with time.
  
• Ulceration, varicosities, and stasis pigmentation do not occur. There may be episodes of lymphangitis and cellulitis.

General Considerations

The underlying mechanism in lymphedema is impairment of the flow of lymph from an extremity. When due to congenital developmental abnormalities consisting of hypo- or hyperplastic changes of the proximal or distal lymphatics, it is referred to as primary lymphedema. Familial lymphedema developing before 1 year of age is called Milroy's disease; it is usually bilateral and affects boys more often than girls. Morecommonly, lymphedema develops during adolescence (lymphedema praecox) and is unilateral; there is a 3.5:1 female predominance. Lymphedema occurring after age 35 years is referred to as lymphedema tarda. The secondary form of lymphedema results from an inflammatory or mechanical obstruction of the lymphatics following trauma, regional lymph node resection, irradiation, bacterial or fungal infections, lymphoproliferative diseases, or filariasis.

Lymphatic obstruction results in stasis of a protein-rich fluid, with slowly progressive, painless edema and secondary fibrosis that may be exacerbated by superimposed episodes of acute infection. The edema is usually centered around the ankle and involves the toes and the dorsum of the foot. Hypertrophy of the limb results, with markedly thickened skin and subcutaneous tissue. Rarely, lymphangiosarcoma or angiosarcoma may develop as a complication of chronic lymphedema. This neoplastic transformation of blood vessels and lymphatics is called the Stewart-Treves syndrome.

Diagnosis is usually made on the basis of clinical findings. Venous duplex ultrasonography is performed to exclude venous insufficiency or vascular malformations. Lymphangiography and radioactive isotope studies are indicated only if surgical reconstruction is anticipated.

Treatment

Lymphedema is a chronic disease for which there is no complete cure. However, a variety of conservative measures can substantially reduce the risk of further complications and disability. No drug therapy is effective. Use of benzopyrones (eg, dicumarol) and corticosteroid injections to increase lymphatic transport has not shown consistent benefit. Diuretics can be useful for acute exacerbation of edema secondary to infection or for coexisting venous stasis disease but are not recommended for long-term use.