Nevi

Last reviewed: March 2019

Last updated: February 2019

Summary

A benign collection of pigment-producing cells (melanocytes) in the epidermis, dermis, or both.

Can be present at birth or shortly thereafter, or acquired throughout childhood, peaking during the third decade.

Seen in all races. Dysplastic or Clark's nevi are more commonly seen in white people.

Melanoma is the most important differential diagnosis when examining melanocytic nevi. Asymmetry, border irregularity, colour variegation, diameter >6 mm, and evolution or change in a pigmented lesion (ABCDEs) may signify concern for malignancy.

Diagnosis is usually clinical, although dermatoscopy and/or biopsy can be utilised to further examine the lesion in cases where there may be uncertainty as to the diagnosis or a concern for malignancy.

Important reasons for removal of a melanocytic nevus are: high clinical suspicion of melanoma; history of change in the lesion, supported by physical examination; and/or high suspicion of atypical features suggestive of melanoma.

Definition

Melanocytic nevi are a group of benign neoplasms or hamartomas made up of melanocytes, the pigment-producing cells of the epidermis. They can present in a variety of ways, most commonly as small, brown, flat macules, raised mammillated dome-shaped papules, bluish-grey macules and papules, and even amelanotic skin-coloured papules. Unless congenital, they first appear in childhood and are more common in people with light skin and eyes. [1]

History and exam

Key diagnostic factors

presence of risk factors
presence since birth
asymmetrical, indistinct or irregularly bordered, variably coloured papules with diameter >5 mm
history of change in shape and colour
asymptomatic (usually)
multiple lesions
flat, brown macule
dome-shaped papule
light brown background with speckled darker brown spots within
blue-grey dome-shaped papule
central pink-to-brown papule with a surrounding depigmented white ring
pinkish-brown papule

Full details

Risk factors

genetic predisposition
UV exposure
fair skin
age: older children and young adults

Full details

Diagnostic investigations

1st investigations to order

dermatoscopy

Full details

Investigations to consider

non-invasive imaging technologies
total body photography
biopsy

Full details

Treatment algorithm

ACUTE

clinically benign

clinically suspicious for melanoma

Contributors

Authors VIEW ALL 

Jason B. Lee, MD

Professor of Dermatology & Cutaneous Biology

Clinical Vice-Chair

Director of Dermatopathology Fellowship

Director of Pigmented Lesion Clinic

Thomas Jefferson University

Philadelphia

Disclosures

JBL declares that he has no competing interests.

Acknowledgements

Dr Jason B. Lee would like to gratefully acknowledge Dr Laurel R. Schwartz, a previous contributor to this topic. LRS declares that she has no competing interests.

Peer reviewers VIEW ALL 

Craig G. Burkhart, MD

Clinical Professor

Department of Medicine

Medical College of Ohio

Toledo

Disclosures

CGB declares that he has no competing interests.

Mark Hurt, MD

Dermatologist

Cutaneous Pathology

WCP Laboratories

Missouri

Disclosures

MH declares that he has no competing interests.

Veronique Bataille, MBBS

Consultant Dermatologist

West Herts NHS Trust and King's College London

London

Disclosures

VB declares that she has no competing interests.

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Nevi

Summary

Definition

History and exam

Key diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Treatment algorithm

clinically benign

clinically suspicious for melanoma

Contributors

Authors VIEW ALL 

Jason B. Lee, MD

Disclosures

Acknowledgements

Peer reviewers VIEW ALL 

Craig G. Burkhart, MD

Disclosures

Mark Hurt, MD

Disclosures

Veronique Bataille, MBBS

Disclosures

Differentials

Guidelines

Patient leaflets

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