Halo Nevus (Mole)

A halo nevus is one type of congenital melanocytic nevus, which is a proliferation of melanocytic cells formed during embryonic life, but after conception. It manifests in adolescence or earlier, in most cases.

It was first described in 1916 and was earlier called the Grunewald nevus. Other names include the Sutton nevus or leukoderma acuisitum centrifugum. It is a rare type, and is so called because of the paler periphery of the lesion in contrast to the hyperpigmented area at the center. The hypopigmentation is due to the autoimmune infiltration by lymphocytes, and forms the ‘halo’ of the lesion’s name.

Observations have showed that the halo nevi last for 10 years or more, but a large subgroup passes through various stages to finally regress completely. The process takes approximately 8 years on average. It is necessary to inform patients that this is what may be expected, so as to prevent the demand for excision in cases where it is not required.

Mechanism

It is hypothesized that the operation of the autoimmune response in the central part of the halo nevus causes destruction of the nevus cells. This is borne out by the fact that histopathological examination fails to show any nevus cells but does reveal a lymphocytic infiltrate.

Types of Halo Nevi

All nevi which have a pale ring or halo around a dark center are not halo nevi. On the basis of their histopathological findings, they may be classified into four forms:

  • Inflammatory
  • Non-inflammatory
  • Halo nevi without halo nevus phenomenon on histopathologic examination
  • Melanocytic nevus with halo dermatitis

True halo nevi are thus extremely rare. In most cases, they are actually compound nevi, junctional nevi, or intradermal nevi. Among true halo nevi, they may show mild to moderate atypical changes in about half of all cases. Severe atypia is also seen in less than 10 percent of halo nevi. Thus, the halo phenomenon alone does not define a halo nevus. Rather, it occurs in association with a wide range of nevi.

Stages of a Halo Nevus

A halo nevus shows a sequence of orderly changes to final regression, as follows:

  • Stage 1: the central part is brown
  • Stage 2: the central part of the lesion becomes depigmented to form a pinkish raised lesion or papule
  • Stage 3: the papule regresses and the central area remains colorless
  • Stage 4: repigmentation progresses to transform the earlier location of the nevus into ordinary skin

Diagnosis and Management

The importance of surveillance of these nevi is that like other melanocytic nevi, these may also give rise to malignant melanoma in 5-10 percent of cases (taking all types together). Many of these nevi are also linked to neurological and skeletal abnormalities as well.

A halo nevus may be associated with melanoma in another distant part of the body. Therefore, the presence of a halo nevus should signal the need for a full body skin examination and ophthalmoscopic examination to rule out intraocular melanoma. Single halo nevi should undergo excision biopsy to exclude the presence of melanom.

References

Further Reading

Last Updated: Feb 27, 2019

Dr. Liji Thomas

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Thomas, Liji. (2019, February 27). Halo Nevus (Mole). News-Medical. Retrieved on October 08, 2024 from https://www.news-medical.net/health/Halo-Nevus-(Mole).aspx.

  • MLA

    Thomas, Liji. "Halo Nevus (Mole)". News-Medical. 08 October 2024. <https://www.news-medical.net/health/Halo-Nevus-(Mole).aspx>.

  • Chicago

    Thomas, Liji. "Halo Nevus (Mole)". News-Medical. https://www.news-medical.net/health/Halo-Nevus-(Mole).aspx. (accessed October 08, 2024).

  • Harvard

    Thomas, Liji. 2019. Halo Nevus (Mole). News-Medical, viewed 08 October 2024, https://www.news-medical.net/health/Halo-Nevus-(Mole).aspx.

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.