Uren, Howman-Giles and Thompson 2003 — Patterns of Lymphatic Drainage from the Skin in Melanoma

Sydney Melanoma Unit series, 3,059 melanoma patients (>3,000 rounded), 1984 onward. Landmark paper establishing that clinical prediction of skin lymphatic drainage is not possible and that Sappey’s-line-based guidelines should be abandoned. Full text now obtained and the quote below is confirmed verbatim (previously only paywall-verified).

Quantitative findings most relevant to our case

Table 2 (posterior trunk, above waist, n=965 — the closest match to a lateral/posterior trunk melanoma):

  • Ipsilateral axillary drainage: 91%
  • Contralateral axillary drainage: 30% (292/965)
  • Bilateral axillary drainage: 27% (264/965)
  • Since “contralateral” and “bilateral” overlap in this table, exclusive contralateral-only drainage (no ipsilateral component) is ~3% (292–264=28/965) — an order of magnitude higher than Chowdhury et al.’s 1.1%, but that cohort measured exclusively contralateral drainage specifically, so the two figures are broadly consistent once definitions are matched.
  • Drainage to the triangular intermuscular space (a then-newly-described, non-axillary, non-groin basin): 9% ipsilateral, 3% contralateral, 1% bilateral — a reminder that “aberrant” drainage in trunk melanoma isn’t limited to crossing the midline; it can also mean reaching an entirely unexpected basin.
  • Multiple node fields overall: 26% of the whole 3,059-patient cohort drained to 2 basins, 7% to 3, 2% to 4.

Verified verbatim quote

Confirmed against full text (p.579, "Anterior Trunk" section)

In fact, we have seen an internal mammary node as a sentinel node for the skin of the anterior trunk in only 2 patients. One had undergone lymph node dissection of the ipsilateral axilla 20 y earlier as a treatment for lymphoma. This procedure presumably caused an alternative lymphatic drainage pathway to appear. The other patient had undergone an extensive excision biopsy of a melanoma in the epigastrium and showed drainage to a sentinel node in the right internal mammary chain as well as to a left axillary sentinel node.

My take

Two distinct contributions to the manuscript now: (1) the quantitative table above gives a real, citable denominator for “how common is contralateral/bilateral axillary drainage in posterior trunk melanoma” — 30% contralateral (albeit mostly alongside ipsilateral drainage, i.e. bilateral), which is far more useful for the Introduction than Chowdhury et al.’s narrower “exclusively contralateral” 1.1%; (2) the 20-year-latency internal-mammary case remains the closest published analogue to this case’s core novelty claim — same causal logic (prior ipsilateral node dissection → alternative pathway appearing decades later), different destination (internal mammary vs contralateral axilla) and different original diagnosis (lymphoma vs melanoma). Cite both parts.