Regression of pigmented lesions in a patient with metastatic melanoma treated with immunotherapy

The programed cell death protein 1 (PD-1) inhibitors nivolumab and pembrolizumab are promising new therapies for the treatment of metastatic melanoma. PD-1 inhibitors function by blocking down regulatory pathways of T-cell activity, thereby increasing T-cell activation and antitumor activity.1 Hypopigmentation, including vitiligo, may occur in up to 15% to 25% of treated patients and is hypothesized to occur by immune destruction of benign melanocytes by antitumor T cells.2,3 We present the case of a patient with metastatic melanoma who experienced fading and disappearance of numerous melanocytic nevi after being treated with PD-1 inhibitors.