A Case of HMB-45 Negative Hypopigmented Cellular Blue Nevus / 대한피부과학회지

Blue nevus is a benign pigmented lesion of dermal melanocytes with a number of histologic and clinical variants. We report a variant of cellular blue nevus that is minimally pigmented. Immunohistochemistry showed the case to be strongly positive with S-100 protein, but negative with Ki-67 and HMB-45 antibody. There is a potential for hypopigmented cellular blue nevus to be confused with other benign nevus, such as intradermal nevus, Spitz nevus, and deep penetrating nevus and malignant melanoma.