Overview
Borderline malignant melanoma, also known as melanoma in situ or lentigo maligna melanoma, represents a precursor lesion to invasive melanoma. These lesions are characterized by atypical melanocytes confined to the epidermis.Diagnosis
Melanoma in situ is diagnosed histopathologically based on the presence of atypical melanocytes within the epidermis 1.
For invasive melanoma, sentinel lymph node biopsy is offered for tumors ≥1.0 mm thickness or ≥0.8 mm with additional histological risk factors, though survival benefit is not yet clear 1.
Therapeutic decisions should be made by an interdisciplinary oncology team 1.Management
Cutaneous melanomas are excised with one to two-centimeter safety margins 1.
Adjuvant therapies can be proposed for completely resected stage IIB-IV melanoma 1.
In stage II, PD-1 inhibitors are approved 1.
In stage III, anti-PD-1 therapy or dabrafenib plus trametinib for BRAFV600 mutated melanoma can be discussed 1.
In resected stage IV, nivolumab or ipilimumab plus nivolumab can be offered in selected, high-risk patients 1.
Neoadjuvant therapy with ipilimumab plus nivolumab followed by complete surgical resection and adjuvant therapy based on pathological response and BRAF status can be offered for clinically detected macroscopic, resectable disease 1.Key Recommendations
Cutaneous melanomas should be excised with one to two-centimeter safety margins 1. (Evidence: Expert opinion)
Sentinel lymph node biopsy should be offered in patients with tumor thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors 1. (Evidence: Expert opinion)
Therapeutic decisions for melanoma should be primarily made by an interdisciplinary oncology team 1. (Evidence: Expert opinion)References
1 Garbe C, Amaral T, Peris K, Hauschild A, Arenberger P, Basset-Seguin N et al.. European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2024. European journal of cancer (Oxford, England : 1990) 2025. link