What is the diagnostic approach for lymphedema?

Diagnostic Approach for Lymphedema

The diagnosis of lymphedema requires a combination of clinical assessment, physical examination findings, and appropriate diagnostic tests, with circumferential measurement being the primary diagnostic method for identifying lymphedema at Stage 1 or greater. 1

Clinical Assessment

• Self-reported symptoms including swelling, heaviness, and numbness should be thoroughly investigated to facilitate early diagnosis 1
• Patient history should identify risk factors such as prior cancer treatment (particularly lymph node dissection), radiation therapy, trauma, infection, or congenital abnormalities 1, 2
• For breast cancer survivors, assess for symptoms in the arm, breast, or chest on the affected side 1

Physical Examination

• Palpate the affected area for fibrosis, pitting, and overall tissue quality 1
• Perform the Stemmer sign test: inability to lift the skin fold at the base of the second toe or finger compared to the contralateral limb indicates lymphedema 1
• Clinical examination using the Modified Head and Neck External Lymphedema and Fibrosis assessment criteria may be used for head and neck lymphedema 1
• Distinguish lymphedema from other causes of edema by evaluating for unilaterality and lack of response to elevation or diuretics 1

Diagnostic Measurements

• Circumferential measurement is the standard method for diagnosing upper extremity lymphedema (Stage 1 or greater) 1
• Water displacement can diagnose lymphedema with volumetry >200 mL compared to the contralateral limb or with volumes >10% interlimb difference 1
• Bioimpedance analysis (BIA) should be used to detect lymphatic transport impairments and diagnose subclinical and early-stage lymphedema (Stage 0 and 1) 1
• L-Dex score of >7.1 should be used as diagnostic criteria for breast cancer-related lymphedema when no preoperative assessment is available 1
• If preoperative measures are available, a 5% or greater volume change from baseline above and below the elbow is diagnostic of upper extremity lymphedema 1

Advanced Imaging

• Ultrasound should be used as a diagnostic tool to identify tissue changes 1
• Lymphoscintigraphy may be used to detect lymphatic system impairment when the diagnosis is uncertain 1
• MRI and CT may be used as diagnostic tools in complex cases 1
• Lymphography may be used to detect lymphatic system impairment in specialized settings 1

Diagnostic Questionnaires

• The following validated questionnaires assist in the diagnosis of secondary upper quadrant lymphedema:
  • Norman Questionnaire 1
  • Morbidity Screening Tool 1

Staging and Referral

• The International Society of Lymphology provides a staging system to categorize the extent of lymphedema 1
• Patients with clinical symptoms or swelling suggestive of lymphedema should be referred to a therapist knowledgeable about lymphedema diagnosis and treatment, such as a physical therapist, occupational therapist, or lymphedema specialist 1
• For breast cancer survivors, referral to a vascular specialist/clinic is recommended if lymphedema is present 1

Common Pitfalls and Caveats

• Obesity can complicate the diagnosis of lymphedema and may cause a false-positive Stemmer sign 1
• In moderate to late-stage lymphedema with fibrosis and tissue changes, BIA measurements may show decreasing extracellular fluid even with increased tissue volume 1
• Perometry may be used for assessment of volume but not as a diagnostic tool 1
• Tonometry is not recommended as a diagnostic tool 1
• Tissue Dielectric Constant may be used for assessment but not as a diagnostic tool 1

By following this systematic diagnostic approach, clinicians can accurately identify lymphedema, allowing for timely intervention to prevent disease progression and complications.