Background: Synthetic peptides that target proopiomelanocortin receptors are being investigated as a novel and safe way to tan. It has been postulated that synthetic alpha-melanocyte-stimulating hormone (alpha-MSH) peptides may have protective effects against the development of melanoma because of their melanogenic activity. Their ultimate biological effect, however, especially in patients with dysplastic nevi or previous melanoma, has yet to be determined.
Observations: A 40-year-old white man with a history of melanoma and multiple dysplastic nevi self-administered synthetic alpha-MSH. He developed crops of new pigmented nevi, many of which had atypical clinical and histopathologic features. The preexisting nevi became darker and acquired growth features. After alpha-MSH use was discontinued, the nevi progressively lightened and lost their growth features.
Conclusions: Synthetic alpha-MSH peptides can drive proliferation of neoplastic melanocytic cells in predisposed patients. This could present an increased risk for melanoma development.