BASICS
DESCRIPTION
Halo nevus is an ordinary nevus in the process of regression. It usually occurs in the 1st or 2nd decade of life and can occur anywhere on the body. The lesion consists of a sharply defined depigmented area surrounding a nevus. Although the central nevus usually disappears over a period of several months to years, the halo may or may not disappear. The halo appears to be an immune response to the melanocytes in the dermal " “epidermal junction. In 1969, Sutton called this lesion leucoderma acquisitum centrifugum and considered it to be a form of vitiligo (1). ‚
EPIDEMIOLOGY
- Halo nevi are uncommon; they affect fewer than 200,000 people in the U.S. population.
- Occurs in both sexes and in all races
- More often seen in teens
- Can occur spontaneously or in patients with vitiligo (18 " “26%)
- Can last a decade or longer
ETIOLOGY AND PATHOPHYSIOLOGY
- Biopsy shows junctional dermal or compound nevus surrounded by lymphocytic infiltrate.
- Nevus cells undergo apoptosis and disappear.
- Considered to be both humoral and cellular immunologic phenomenon
- The infiltrating cells are predominantly T lymphocytes, and cytotoxic (CD8) lymphocytes outnumber helper (CD4) lymphocytes by a ratio of ~4:1.
- Decrease or total absence of melanin and melanocytes in the halo
RISK FACTORS
- Family history of vitiligo
- Family history of halo nevi
COMMONLY ASSOCIATED CONDITIONS
Vitiligo (26% of cases) ‚
DIAGNOSIS
HISTORY
Patients will note that a mole is changing. ‚
PHYSICAL EXAM
- Brown papular lesion with sharply marginated oval or round halo (area of depigmentation)
- <5 mm
- Located on trunk but can be anywhere on body
- May begin with erythema or inflammation of the central nevus
DIFFERENTIAL DIAGNOSIS
- Congenital nevus
- Blue nevus
- Spitz juvenile nevus
- Verruca plana
- Primary melanoma
- Melanoma metastasis
- Dermatofibroma
- Neurofibroma
DIAGNOSTIC TESTS & INTERPRETATION
This is a clinical diagnosis. None required ‚
Diagnostic Procedures/Other
- Wood lamp: shows depigmentation
- Biopsy: only if the central nevus shows irregular border or variegation of color
- Dermoscopy
- Globular or homogenous patterns indicating a benign nature (2)
- Appearance similar to benign melanocytic nevi (2)
Test Interpretation
Lymphocytic infiltrate in dermal " “epidermal junction surrounding a junction dermal or compound nevus ‚
TREATMENT
- Reassurance
- Biopsy only if suspicious for dysplasia or melanoma
MEDICATION
- No treatment is indicated.
- Benign halo nevi are only of cosmetic concern and patients are asymptomatic.
- Treatment with 12 months of topical tacrolimus is experimental currently, but it has shown regression in patients with focal vitiligo and benign halo nevus (3). At this time, more research will need to be conducted.
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
Advise patient to have an annual skin cancer screening. ‚
PATIENT EDUCATION
- Advise about the warning signs of skin cancer and melanoma.
- Educate patient about sun avoidance/sunscreen usage.
- Inform patient about the association with vitiligo.
- Advise patient that family members can develop similar lesions.
- Lesion may regress after about a decade, which can possibly prevent unnecessary excision, but annual exams are advised.
- Spontaneous partial or complete repigmentation may occur overtime in cases that seem to be associated with vitiligo
PROGNOSIS
Favorable, as it is rarely malignant. ‚
REFERENCES
11 Sutton ‚ RL. An unusual variety of vitiligo (leukoderma acquisitum centrifugum). J Cutan Dis. 1969;34:797 " “800.22 Terushkin ‚ V, Scope ‚ A, Halpern ‚ AC, et al. Pathways to involution of nevi: insights from dermoscopic follow-up. Arch Dermatol. 2010;146(4):459 " “460.33 Delwar ‚ H. Treating benign halo nevus and focal vitiligo with topical tacrolimus: a brief report. Am J Clin Exp Med. 2014;2(5):103 " “105.
CODES
ICD10
- D22.9 Melanocytic nevi, unspecified
- D22.5 Melanocytic nevi of trunk
ICD9
- 216.9 Benign neoplasm of skin, site unspecified
- 216.5 Benign neoplasm of skin of trunk, except scrotum
SNOMED
Halo nevus ‚
CLINICAL PEARLS
- Halo nevus is a benign finding.
- A 3-month follow up to reevaluate the need for biopsy may be advisable. Biopsy if other characteristics are suggestive of a malignant lesion
- A photograph is very valuable for accurate follow-up.