Vitiligo-Like Depigmentation in Nivolumab-Treated Nodular Melanoma: A Paradoxical Clinical Course

Vitiligo-like depigmentation (VLD) is a recognized cutaneous adverse event associated with anti-programmed cell death protein-1 (anti-PD-1) therapy in patients with melanoma and has been linked to favorable therapeutic response and improved survival outcomes. We present the case of a 72-year-old woman diagnosed with metastatic nodular melanoma treated with nivolumab monotherapy, who developed disseminated VLD after multiple treatment cycles. Despite achieving an initial complete radiologic response and developing extensive depigmentation, the patient subsequently experienced disease progression, presenting hepatic, pulmonary, and central nervous system metastases. This case contrasts with the commonly reported association between VLD and favorable prognosis, emphasizing that this phenomenon may not consistently predict sustained clinical benefit in patients receiving immunotherapy for advanced melanoma.