A case report of metastatic melanoma in the popliteal fossa

Sarah Catania1, Anthony Pio Dimech1, Kevin Cassar2

  • 1Department of Surgery, Mater Dei Hospital, Triq Dun Karm, L-Imsida, MSD 2020, Malta.

Abstract

Insights

Metastatic melanoma rarely spreads to the popliteal fossa, but overlooked popliteal lymph node metastasis can cause recurrence. Early detection through thorough assessment is crucial for managing lower extremity melanomas.

Area of Science:

  • Oncology
  • Surgical Oncology
  • Dermatology

Background:

  • Metastatic melanoma to the popliteal fossa is rare, accounting for less than 5% of lower extremity melanoma metastases.
  • The majority of melanoma metastases in the leg and foot drain to the inguinal region.
  • Overlooking popliteal spread can lead to melanoma recurrence.

Observation:

  • A 66-year-old male presented with metastatic melanoma in the right popliteal fossa.
  • This occurred three years after diagnosis of a primary melanoma on the right mid-calf.
  • The patient had also undergone ipsilateral inguinal lymph node dissection.

Findings:

  • Melanoma lesions below the knee can metastasize to the popliteal fossa.
  • The groin can be a primary or secondary lymphatic drainage site alongside the popliteal fossa.
  • Concurrent popliteal and inguinal drainage suggests complex lymphatic pathways.

Implications:

  • Popliteal lymph nodes require careful assessment for distal lower extremity lesions, including melanomas.
  • Modalities to delineate lymphatic flow and identify micrometastatic deposits are recommended.
  • Radical popliteal dissection is advised for identified metastatic popliteal disease.