What causes lymphedema in the flanks?

Causes of Lymphedema in the Flanks

Lymphedema in the flanks is primarily caused by damage or obstruction to the lymphatic system, resulting in accumulation of protein-rich interstitial fluid and fibroadipose tissue. 1

Primary Causes

• Congenital abnormalities of the lymphatic system can lead to primary lymphedema affecting any body region, including the flanks 2

Secondary Causes (More Common)

• Cancer treatment-related factors:

  • Surgical lymph node dissection, particularly extensive procedures removing five or more lymph nodes 1, 3
  • Radiation therapy, especially when directed at lymph node regions that drain the trunk and flanks 3, 1
  • Combined treatment with both surgery and radiation therapy significantly increases risk 1

• Other secondary causes:

  • Recurrent infections in the affected area can damage lymphatic vessels and lead to lymphedema 1
  • Trauma to lymphatic vessels in the abdominal/flank region 4
  • Underlying systemic diseases affecting lymphatic function 4

Risk Factors

• Obesity (BMI >30 kg/m²) is a significant risk factor that can:

  • Increase pressure on lymphatic vessels
  • Complicate diagnosis
  • Exacerbate existing lymphedema 1, 3

• Extent of lymph node removal correlates with risk - more extensive dissection creates higher risk 3, 1

Pathophysiology

• Damage to lymphatic vessels leads to lymphatic fluid stasis, triggering three key mechanisms:

  • Inflammation involving CD4+ T cells as the principal contributing factor 5
  • Adipocyte hypertrophy and adipose tissue deposition 5
  • Tissue fibrosis initiated by overactivity of Th2 cells 5

• The stagnant protein-rich lymph initiates an inflammatory cascade that leads to:

  • Progressive fibrosis
  • Adipose tissue accumulation
  • Increased susceptibility to infections 6

Clinical Presentation

• Swelling that may be unilateral or bilateral
• Lack of response to elevation or diuretics
• Progressive worsening if untreated 1

Complications

• Increased risk of cellulitis and recurrent infections 3, 1
• Potential for development of rare malignancies in chronically lymphedematous tissue (e.g., lymphangiosarcoma) 7
• Functional limitations and decreased quality of life 4

Common Pitfalls in Diagnosis

• Failure to differentiate lymphedema from other causes of edema can lead to delayed diagnosis 1
• Misdiagnosis is common as lymphedema can mimic other conditions causing extremity or trunk swelling 4
• Delayed treatment allows progression and increases risk of complications 2

Management Considerations

• Early identification and referral to a specialist in lymphedema management is crucial 3
• Weight management is recommended for patients who are overweight or obese 3, 2
• Prompt treatment of infections with antibiotics is essential to prevent worsening 2