Multifocal BRAF_V600E-Mutated Melanoma in situ on the Foot

Melanoma is an aggressive skin cancer that originates from melanocytes, and about one half of melanoma cases possess a BRAF mutation. Together with PD-L1 expression, the BRAF^V600E mutation is one of the optimal therapeutic targets for the treatment of melanoma. In this report, we describe a case of multifocal melanoma in situ on the foot, which carried the p.V600E mutation in the BRAF gene. Interestingly, the spotted melanoma lesion is demarcated by normal skin, and in all spotted pigmented lesions, there were no signs of dermal invasion of melanoma cells or spontaneous regression. Our case presented atypical clinical features, which might correlate with the local mutations of BRAF gene and the immunological expression of PD-L1.