A Case of Amelanotic Melanoma in the Setting of Cemiplimab Therapy for Invasive Squamous Cell Carcinoma

Cemiplimab is the first PD-1 inhibitor approved in the United States for the treatment of metastatic or locally advanced cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), but not melanoma. We describe a case of amelanotic melanoma (AM) developing in a patient on cemiplimab therapy for invasive SCC. Cutaneous AM is a rare subtype of cutaneous melanoma that shows little or no melanin pigmentation on clinical and histological examination thus often leading to a high misdiagnosis rate. Physicians should consider atypical presentations of melanoma, including amelanotic melanoma, during surveillance of patients managed with immune checkpoint inhibitor therapy.