Diagnosis and measurement

Evidence in one minute

• Diagnosis is clinical in most patients (history, pitting, Stemmer sign, skin changes, limb shape). In adult unilateral oedema exclude tumour obstruction; duplex to exclude DVT/venous disease. Executive Committee of the International Society of Lymphology 2023
• Lymphoscintigraphy is the core confirmatory test (not standardised); ICG lymphography stages superficial lymphatic function and plans LVA; MR lymphography in specialist centres; oil-contrast lymphography only for chylous reflux/thoracic duct. Avoid biopsy of enlarged nodes in long-standing lymphoedema. Historic SA contrast lymphangiography series: Abramowitz 1971 · Smith 1966.
• Always measure both limbs and report excess volume — ignoring the control limb overestimates treatment effect; 4 cm leg segments are not needed (8–12 cm agree). Moderate certainty (large retrospective data). Mayrovitz 2007
• Tissue dielectric constant (TDC) measures local skin-to-fat water (~2.5 mm): no dominance effect, site- and depth-specific normal values; one reading suffices; affected/contralateral forearm ratio in established BCRL ~1.6; proposed pre-clinical threshold ≥1.2 (2014) or 1.26 (2009) — derived from control variability, not validated prospectively. Low certainty for diagnostic use. Mayrovitz 2014 · Mayrovitz 2009 · Mayrovitz 2008 · Mayrovitz 2009
• TDC detects local change girth misses (one MLD session: TDC −9.8% vs girth −1.5%). Mayrovitz 2008
• Bioimpedance detects early extracellular fluid change (pilot after gynaecological node dissection). Takeuchi 2013
• Prospective surveillance: baseline bilateral measurement before cancer surgery, then ~3-monthly in year 1; subclinical threshold 3–5% volume change (ISL). The SA referral pathway proposes pre-treatment limb measurement for every newly diagnosed breast cancer. Marco 2014
• Lymphoedematous arms are not hypoxic on TcPO2 — a low reading suggests another cause. Mayrovitz 2005
• ABPI before leg compression — often unreliable in oedematous limbs (cuff size, clinical correlation); UK guidance allows ≤20 mmHg before ABPI if no red flags. Keast 2025 · Fletcher 2024