This case report describes a 54-year-old patient with Xeroderma Pigmentosum (XP) who developed unresectable cutaneous squamous cell carcinoma (cSCC) and was treated with pembrolizumab, an immune checkpoint inhibitor (ICI). The treatment led to significant tumor regression and, unexpectedly, a complete resolution of the patient’s lentigines, while vitiligo and other pigmented lesions remained unchanged. The findings suggest that ICIs may amplify immune responses against UV-induced pigmented lesions in XP patients, potentially linked to the disease’s high mutational burden, though further studies are needed to elucidate the underlying mechanisms.
Brufau-Cochs et al. (Wed,) studied this question.