The HALO NEVUS - also known as SUTTON NEVUS - is a peculiar variant of the COMPOUND NEVUS and found quite frequently among younger individuals (adolescence). In addition to the features described for the COMPOUND NEVUS, they are surrounded by a anular circle of depigmented (white) skin, resembling the planet SATURN. This area of depigmentation may be less or more pronounced, it may even involve the central pigmented spot lesion in its entirety so that the resulting aspect is that of an oval white spot with no signs of melanin pigment inside.

Reason for that peculiar aspect is a pronounced inflammatory reaction inside the lesion, invisible and imperceivable to the lesion's carrier. Itr can only been seen under the microscope on histological exploration. Numerous inflammatory mediator cells (lymphocytes, macrophages) are infiltration the MELANOCYTE CLUSTERS, eventually destroying them and replacing their area by fibrous tissue (scar tissue). To date, the causation for this process is not known, however, it is speculated whether or not this finding might be interpreted as a model for auto-immune mechanisms that exert cell growth regulation directed specifically at MELANOCYTES. If this would turn out to be true, this model could serve a pattern model for the experimental treatment design in MELANOMA. It could then be hoped that targeted initiation of this mechanism could destroy MELANOMA CELLS likewise, thus leading to the self-destruction of tumorous tissue.

The HALO NEVUS is benign and doesn't require further action. It should, however, be monitored, since individuals presenting with HALO NEVI do indicate that something's going on in their MELANOCYTIC SYSTEM.