Utilization of p16, p21, Ki67, HMB-45, and Prame Immunohistochemistry in Melanocytic Lesions

Summary: Malignant melanoma is the most aggressive and leading cause of death due to cutaneous neoplasms. Diagnosis of melanoma in its early stages followed by surgical resection is associated with favorable survival rates. However, a frequent discordance among dermatopathologists has been reported in diagnosing a portion of indeterminate melanocytic tumors. Several immunohistochemical (IHC) markers have been reported to assist in differentiating benign nevi from malignant melanoma, including p16, p21, Ki67 (MIB1), HMB-45, and PReferentially expressed Antigen in MElanoma (PRAME). Hypothesis: A panel of important immunohistochemical markers may be more helpful in the diagnosis of challenging melanocytic lesions than any single IHC marker.