You are in: eMedicine Specialties > Dermatology > BENIGN NEOPLASMS Halo NevusArticle Last Updated: Feb 26, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Edward J Zabawski Jr, DO, RPh, Dermatology, Spencer Dermatology Group, Crawfordsville, IN Coauthor(s): Clay J Cockerell, MD, Director, Clinical Professor, Department of Dermatology, Division of Dermatopathology, University of Texas Southwestern Medical Center Editors: Susan M Swetter, MD, Director, Pigmented Lesion and Cutaneous Melanoma Clinic, Associate Professor, Department of Dermatology, Stanford University Medical Center, Veterans Affairs Palo Alto Health Care System; Richard P Vinson, MD, Assistant Clinical Professor, Department of Dermatology, Texas Tech University School of Medicine; Consulting Staff, Mountain View Dermatology, PA; Jeffrey Meffert, MD, Assistant Clinical Professor of Dermatology, University of Texas Health Science Center-San Antonio; Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University; William D James, MD, Paul R Gross Professor of Dermatology, University of Pennsylvania School of Medicine; Vice-Chair, Program Director, Department of Dermatology, University of Pennsylvania Health System Author and Editor Disclosure Synonyms and related keywords: nevus of Sutton, halo nevi, Sutton nevus, Sutton nevi, melanoma, malignant melanoma INTRODUCTIONSection 2 of 10
  BackgroundHalo nevi are common benign skin lesions that represent melanocytic nevi in which an inflammatory infiltrate develops, resulting in a zone of depigmentation surrounding the nevus. Although Sutton originally described the lesion in 1916 as leukoderma acquisita centrifugum, the lesions were noted earlier, as evidenced by their depiction in the painting The Temptation of Saint Anthony by Matthias Grunewald circa 1512-1516. Because melanoma that has undergone regression may appear gray or white, halo nevi have been erroneously confused with melanoma and have been the source of much anxiety among both clinicians and patients. Nevertheless, they are entirely benign lesions and of only cosmetic significance. PathophysiologyThe etiology of halo nevi is unknown. Numerous studies have attempted to unravel the immunologic mechanisms by which an immune response develops to existing aggregates of nevus cells. The infiltrating cells are predominantly T-lymphocytes, and cytotoxic (CD8) lymphocytes outnumber helper (CD4) lymphocytes by a ratio of approximately 4:1. These, as well as scattered macrophages, comprise most inflammatory cells in halo nevi. As seen in vitiligo, melanocytes in the epidermis in the halo component of the nevus are completely absent, suggesting a similar etiologic mechanism. The exact role that the lymphocytes play in the regression of halo nevi has not been fully determined, although a theory of direct cytotoxic effects on melanocytes seems plausible. Of interest, circulating antibodies to the cytoplasm of melanoma cells have been detected in patients with halo nevi. Because these antibodies have disappeared after removal of the halo nevus, they were thought to be related. Subsequent investigation failed to reveal a temporal relation between the appearance of these antibodies and the regression of nevus cells, and these antibodies are now believed to appear as a consequence of the release of cytoplasmic proteins of halo nevus melanocytes secondary to cell damage. Ultrastructurally, advanced lesions of halo nevus show dermal macrophages containing portions of nevus cells. While it is clear that an immunologic mechanism results in the demise of melanocytes in halo nevi, the precipitating cause and the exact role of the lymphocytes remain unknown. FrequencyUnited StatesThe incidence of halo nevi in the population is estimated to be 1%. Patients with Turner syndrome have been reported to have an increased incidence of halo nevi. Mortality/MorbidityHalo nevi are benign. Morbidity is minimal and limited to cosmetic appearance. RaceAll races are susceptible to the development of these lesions. A familial tendency for halo nevi has been reported. SexNo sexual predilection is reported. AgeHalo nevi are found most commonly in children. The average age of onset is 15 years. CLINICALSection 3 of 10
HistoryPatients with halo nevi are usually asymptomatic. The central nevus may or may not involute with time. Repigmentation often takes place over months or years; however, it does not always occur. Occasionally, inflammation occurs with crusting in the depigmented zone of a halo nevus. Most commonly, the chief complaint is that of a changing mole (or moles). PhysicalHalo nevi are usually single but may be multiple. They can develop anywhere on the body but are seen most frequently on the trunk. Clinically, they appear as one or more uniformly colored, evenly shaped, round or oval nevi centrally with even peripheral margins of hypopigmentation. The central nevus may be tan, pink, or brown. The width of the halo is variable but is generally of uniform radial distance from the central nevus (see Image 1). CausesThe cause is unknown, but halo nevus is believed to be due to an immune response against melanocytes. DIFFERENTIALSSection 4 of 10
Atypical Mole (Dysplastic Nevus) Basal Cell Carcinoma Lichen Planus Lichen Sclerosus et Atrophicus Malignant Melanoma Molluscum Contagiosum Pityriasis Lichenoides Spitz Nevus Vitiligo
| ||||||||||||||||||||||||||||||||||||||||
| Halo Nevus | Melanoma |
|---|---|
| Nevus cells in nests | Single atypical melanocytes at all levels of the epidermis and aggregates of atypical melanocytes in the dermis |
| Lesion symmetrical | Lesion asymmetrical |
| Maturation of nevus cells | Lack of maturation |
| Mitotic figures rare or absent | Mitotic figures present |
| Lymphocytic infiltrate present diffusely throughout lesion | Lymphocytic infiltrate tends to be at be concentrated at periphery |
Halo nevi are benign, and no treatment is necessary.
The chief diagnostic consideration in patients with halo nevi is melanoma that is undergoing regression, although making this distinction is not usually difficult. Primary melanoma is usually solitary, whereas halo nevi are commonly multiple. Furthermore, children are affected more commonly with halo nevi; adults are affected far more commonly by melanoma.
Melanomas with surrounding white or hypopigmented zones usually have been present for an extended period of time, and the white areas represent zones of regression. Thus, the "halo" of a regressing melanoma is irregular in shape and variable in radial width, as opposed to the evenly distributed, circular zone of hypopigmentation in true halo nevi, which is distributed around the central nevus. Furthermore, melanomas usually exhibit the characteristic clinical signs of breadth, asymmetry, poor circumscription, and color irregularity with black foci that usually allow the diagnosis to be rendered with relative ease.
In spite of clinically benign features, the presence of a new "halo nevus" in an older adult should be regarded with a high index of suspicion for melanoma and may warrant performing a biopsy. In those patients where a potential malignancy is in question, a dermatologist should be consulted.
| Media file 1: Classic appearance of a halo nevus. | |
 | View Full Size Image | Media type: Photo |
| Media file 2: Note the central pink papule (intradermal nevus) and the surrounding halo. The halo is of uniform width at all points, and no inflammatory component can be seen. Note the normal nevus directly inferior. | |
 | View Full Size Image | Media type: Photo |
| Media file 3: At low magnification, a dome-shaped papular lesion reveals a dense infiltrate of lymphocytes in the dermis (hematoxylin and eosin, original magnification X40). | |
 | View Full Size Image | Media type: Image |
| Media file 4: Higher magnification reveals nests of nevus cells with numerous lymphocytes surrounding them and in the interstitium (hematoxylin and eosin, original magnification X40). | |
 | View Full Size Image | Media type: Image |
Article Last Updated: Feb 26, 2007
