Management of Malignant Melanoma of Foot with Fungating Groin Node
For a patient with malignant melanoma of the foot presenting with a fungating groin lymph node, this represents unresectable/metastatic stage IV disease requiring systemic immunotherapy as first-line treatment, with surgical debulking of the fungating node for local control and symptom management.
Initial Assessment and Staging
The presence of a fungating groin node indicates bulky, clinically evident nodal disease that has likely progressed beyond the capsule with extracapsular spread. This clinical presentation suggests:
- Stage IV disease (unresectable regional or distant metastatic disease)
- Poor prognostic features: Fungating nodes indicate aggressive biology with extracapsular spread, which significantly impacts survival 1
- Immediate need for BRAF mutation testing to guide systemic therapy selection 2
Obtain whole-body CT or PET-CT plus brain MRI to assess for distant metastases, as recommended for advanced stage disease 3.
Primary Treatment Strategy
1. Systemic Therapy (First Priority)
The fungating nature and likely unresectable disease mandates systemic therapy as the primary treatment modality:
For BRAF wild-type disease, offer 2:
- Ipilimumab plus nivolumab followed by nivolumab maintenance (preferred for high disease burden)
- OR nivolumab monotherapy
- OR pembrolizumab monotherapy
For BRAF V600-mutant disease, offer 2:
- Ipilimumab plus nivolumab followed by nivolumab maintenance
- OR nivolumab monotherapy
- OR pembrolizumab monotherapy
- OR dabrafenib plus trametinib
- OR encorafenib plus binimetinib
- OR vemurafenib plus cobimetinib
Critical decision point: For bulky, symptomatic disease with fungating nodes, combination ipilimumab plus nivolumab provides the highest response rates despite increased toxicity, making it the preferred option for patients who can tolerate it 2.
2. Surgical Management of Fungating Node
Palliative surgical debulking or complete groin dissection should be performed for:
- Local symptom control (bleeding, pain, infection, odor)
- Improved quality of life
- Potential enhancement of systemic therapy efficacy
- If disease appears limited to superficial inguinal nodes: superficial inguinal lymph node dissection (SLND)
- If palpable or radiologically positive deep/pelvic nodes: combined superficial inguinal and pelvic lymph node dissection (ilioinguinal dissection)
- Ilioinguinal dissection carries no increased morbidity compared to SLND and provides better regional control 1, 4
The presence of extracapsular spread (evident from fungating presentation) is a significant negative prognostic factor, with 5-year survival dropping substantially 1.
Sequencing of Treatment
Optimal approach:
- Initiate systemic immunotherapy immediately after BRAF testing
- Perform surgical debulking within 2-4 weeks once patient is medically optimized
- Continue systemic therapy postoperatively (immunotherapy can continue for up to 2 years for pembrolizumab, beyond 2 years for nivolumab) 2
Management of Primary Foot Melanoma
The primary foot lesion requires wide local excision with appropriate margins based on Breslow thickness:
- Margins of 2 cm for lesions >1.5 mm thick (most likely given nodal metastases) 5
- May require skin grafting or partial amputation depending on location 5
- If subungual location: digital amputation is required for local control 5
Common Pitfalls to Avoid
- Do not delay systemic therapy for surgical planning—fungating nodes indicate aggressive disease requiring immediate systemic control
- Do not perform only superficial groin dissection if deep nodes are clinically or radiologically positive—this compromises regional control 1, 4
- Do not consider this resectable stage III disease—fungating nodes typically indicate unresectable disease requiring stage IV treatment protocols
- Do not use adjuvant therapy protocols—this patient requires treatment for unresectable/metastatic disease, not adjuvant therapy 2
Prognosis
With fungating groin nodes and extracapsular spread, expect: