Abstract: A 72-year-old female presented with malignant mass on the right forehead for one year and relapsed for one month. Biopsy showed an active proliferation of melanocytes, clustered together in the dermis with proliferation of atypical melanocytes. Immunohistochemistry revealed S100-positive within the dermis. Genetic testing showed that PD-L1 immunohistochemistry was positive by 10.00% and no mutation was found in the BRAF gene. The diagnosis of melanoma was made. The patient was treated with Keytruda, PD-1/PD-L1 targeted blocker drug for 6 courses, but the lump was still expanding and the patient lost vision in her right eye.