A patient with a junctional component from a nevus spilus surrounded by an achromic halo on the right thigh is reported. The link between the immune response to melanoma and the mechanism responsible for halo nevus is closely related. There is evidence that the halo phenomenon results from a mediated cell immunologic reaction against an unknown antigen present in melanocytic lesions. Antibodies are also found in these lesions.
immunity; melanoma; nevus; pigmented