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Skin: Management of a positive sentinel lymph node

Free question published 19 August 2026

SkinManagement of a positive sentinel lymph node

A 51-year-old man with a 2.4 mm ulcerated melanoma of the thigh undergoes wide local excision and sentinel lymph node biopsy. One sentinel node in the groin contains a 0.6 mm micrometastatic deposit. Staging CT shows no further nodal or distant disease, and the remaining groin is clinically and sonographically normal. He is keen to do everything possible. What is the most appropriate management of the regional nodal basin?

  1. AImmediate completion inguinal lymph node dissection to improve melanoma-specific survival
  2. BAdjuvant inguinal radiotherapy in place of any surgery
  3. CNodal observation with ultrasound surveillance, as completion dissection does not improve melanoma-specific survival
  4. DRepeat sentinel lymph node biopsy in three months
  5. EIsolated limb perfusion of the affected leg

Why C is correct

MSLT-II showed that immediate completion lymph node dissection after a positive sentinel node increased regional disease control and provided prognostic information but did not improve melanoma-specific survival (86% in both arms at 3 years), while markedly increasing lymphoedema (24.1% vs 6.3%). NICE NG14 accordingly advises against routine completion dissection for micrometastatic stage III disease, favouring nodal observation with ultrasound.

And why the others are not

  • AIncorrect: MSLT-II found no melanoma-specific survival benefit from immediate completion lymph node dissection, which only adds morbidity such as lymphoedema.
  • BIncorrect: adjuvant nodal radiotherapy is not indicated for a single micrometastatic node and does not replace appropriate surveillance or systemic options.
  • DIncorrect: repeat sentinel node biopsy is not a recognised management step once a positive node has been identified.
  • EIncorrect: isolated limb perfusion is used for unresectable in-transit metastases, not for a microscopically positive sentinel node.

Source MSLT-II - Completion dissection or observation for sentinel-node metastasis in melanoma — Faries MB, Thompson JF, Cochran AJ, et al. Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma. N Engl J Med. 2017;376(23):2211-2222.

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