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| Fig. 41.1 A, Junctional nevi are typically small, flat, and dark brown in color. B, An intradermal nevus also may be very exophytic or papillomatous, as shown here. C, Typical halo nevus of the back demonstrating a central brownish-red papule. D, Large congenital nevus with multiple smaller congenital nevi. These lesions present a surgical challenge and a significant cosmetic problem. |
A halo nevus, also known as a Sutton’s nevus or leukoderma acquisitum centrifugum, is a melanocytic nevus with a surrounding well-circumscribed annulus of hypo- or depigmented skin (Fig. 41-1C). Halo nevi can be solitary or multiple and generally affect individuals under the age of 20 years. In general, those patients with halo nevi have an overall increased number of melanocytic nevi. Halo nevi are commonly associated with vitiligo, with ~20% to 50% of vitiligo patients demonstrating halo nevi. Conversely, ~15% to 25% of patients with halo nevi have vitiligo. Although both halo nevi and vitiligo may look similar clinically, recent studies strongly suggest that halo nevi and vitiligo have separate pathogenetic mechanisms. Although not completely understood, the pathogenesis of halo nevi is thought to be related to :
1. an immune response against antigenically altered nevus cells or
2. a cell-mediated or humoral immune response against nonspecifically altered nevus cells.
It is not completely understood whether this represents an abnormal immunologic response or whether the immune system is recognizing an atypical clone of nevomelanocytes.
Although most pigmented lesions with halos are benign, malignant melanoma can rarely be seen with an associated halo. If a pigmented lesion has an irregular border and halo or shows other atypical features, it should be biopsied.
De Vijlder HC, Westerhof W, Schreuder GM, et al: Difference in pathogenesis between vitiligo vulgaris and halo nevi associated with vitiligo is supported by an HLA study,
Pigment Cell Res 17:270–274, 2004.
