Nevus

Not to be confused with Naevius, Nevis, or Nevius.

"Polychromia" redirects here. For the red blood cell disorder, see Polychromasia.

Nevus

Other names: nevi
A benign nevus

Nevus (plural nevi) is a nonspecific medical term for a visible, circumscribed, chronic lesion of the skin or mucosa.[1][2] The term originates from nævus, which is Latin for "birthmark"; however, a nevus can be either congenital (present at birth) or acquired. Common terms, including mole, birthmark, and beauty mark, are used to describe nevi, but these terms do not distinguish specific types of nevi from one another.

## Contents

* 1 Classification
* 1.1 Increased melanin
* 1.1.1 Usually acquired
* 1.1.2 Usually congenital
* 1.2 Decreased melanin
* 1.2.1 Acquired
* 1.2.2 Congenital
* 1.3 Epidermal nevi
* 1.4 Connective tissue nevi
* 1.5 Vascular nevi
* 1.6 Intramucosal nevi
* 2 Diagnosis
* 2.1 Differential diagnoses
* 3 Management
* 3.1 Observation
* 3.2 Destruction
* 3.3 Surgery
* 4 Syndromes
* 5 Etymology
* 6 See also
* 7 References
* 8 External links

## Classification[edit | edit source]

The term nevus is applied to a number of conditions caused by neoplasias and hyperplasias of melanocytes,[3] as well as a number of pigmentation disorders, both hypermelanotic (containing increased melanin, the pigment responsible for skin color) and hypomelanotic (containing decreased melanin).[4] Suspicious skin moles which are multi-colored or pink may be a finding in skin cancer.[5]

### Increased melanin[edit | edit source]

#### Usually acquired[edit | edit source]

* Melanocytic nevus
* Melanocytic nevi can be categorized based on the location of melanocytic cells[3]
* Junctional: epidermis
* Intradermal: dermis
* Compound: epidermis and dermis
* Atypical (dysplastic) nevus: This type of nevus must be diagnosed based on histological features. Clinically, atypical nevi are characterized by variable pigmentation and irregular borders.[6]
* Becker's nevus
* Blue nevus (rarely congenital): A classic blue nevus is usually smaller than 1 cm, flat, and blue-black in color.[7]
* Hori's nevus
* Nevus spilus (speckled lentiginous nevus): This lesion includes dark speckles within a tan-brown background.[8]
* Pigmented spindle cell nevus
* Spitz nevus
* Zosteriform lentiginous nevus

#### Usually congenital[edit | edit source]

* Congenital melanocytic nevus
* These nevi are often categorized based on size, however, the lesions usually grow in proportion to the body over time, so the category may change over an individual's life.[3] This categorization is important because large congenital melanocytic nevi are associated with an increased risk of melanoma, a serious type of skin cancer.[3]
* Small: <1.5 cm[3]
* Medium: 1.5–19.9 cm[3]
* Large: ≥ 20 cm[3]
* Nevus of Ito
* Nevus of Ota

* Conjunctival nevus of a 32-year-old male

* Micrograph of an intradermal melanocytic nevus

* Acquired melanocytic nevi

* Atypical nevus

* Becker's nevus

* Blue nevus

* Nevus spilus

* Spitz nevus

* Congenital melanocytic nevus

* Nevus of Ota

* Compound nevus, left buttock

### Decreased melanin[edit | edit source]

#### Acquired[edit | edit source]

* Nevus anemicus

#### Congenital[edit | edit source]

* Nevus depigmentosus

* Nevus anemicus

* Nevus depigmentosus

Additional types of nevi do not involve disorders of pigmentation or melanocytes. These additional nevi represent hamartomatous proliferations of the epithelium,[9] connective tissue,[10] and vascular malformations.[11]

### Epidermal nevi[edit | edit source]

These nevi represent excess growth of specific cells types found in the skin, including those that make up oil and sweat glands.[9]

* Verrucous epidermal nevus
* Nevus sebaceous
* Nevus comedonicus
* Eccrine nevus
* Apocrine nevus

### Connective tissue nevi[edit | edit source]

Connective tissue nevi represent abnormalities of collagen in the dermis, the deep layer of the skin.[10]

* Collagenoma
* Elastoma

### Vascular nevi[edit | edit source]

These nevi represent excess growth of blood vessels, including capillaries.[12]

* Nevus simplex, also known as a salmon patch includes types known as nevus flammeus nuchae (stork bite)

* Nevus sebaceous

* Nevus flammeus nuchae

### Intramucosal nevi[edit | edit source]

An intramucosal nevus is a nevus within the mucosa as found in for example the mouth and genital areas. In the mouth, they are found most frequently on the hard palate. They are typically light brown and dome-shaped.[13] Intramucosal nevi account for 64% of all reported case of oral nevi.[14]

## Diagnosis[edit | edit source]

Various differential diagnoses of pigmented skin lesions, by relative rates for biopsied lesions, and malignancy potential, including "nevus" at left and top.

Nevi are typically diagnosed clinically with the naked eye or using dermatoscopy. More advanced imaging tests are available for distinguishing melanocytic nevi from melanoma, including computerized dermoscopy and image analysis.[15] The management of nevi depends on the type of nevus and the degree of diagnostic uncertainty. Some nevi are known to be benign, and may simply be monitored over time. Others may warrant more thorough examination and biopsy for histopathological examination (looking at a sample of skin under a microscope to detect unique cellular features). For example, a clinician may want to determine whether a pigmented nevus is a type of melanocytic nevus, dysplastic nevus, or melanoma as some of these skin lesions pose a risk for malignancy. The ABCDE criteria (asymmetry, border irregularity, color variegation, diameter > 6 mm, and evolution) are often used to distinguish nevi from melanomas in adults, while modified criteria (amelanosis, bleeding or bumps, uniform color, small diameter or de novo, and evolution) can be used when evaluating suspicious lesions in children.[16] In addition to histopathological examination, some lesions may also warrant additional tests to aid in diagnosis, including special stains, immunohistochemistry, and electron microscopy.[17] Typically, the nevi that exist since childhood are harmless.

* A modern polarized dermatoscope

* A dermatoscope

### Differential diagnoses[edit | edit source]

Hypermelanotic nevi must be differentiated from other types of pigmented skin lesions, including:[7][8]

* Lentigo simplex
* Solar lentigo
* Café au lait macule
* Ink-spot lentigo
* Mucosal melanotic macule
* Mongolian spot (dermal melanocytosis)

* Cafe au lait

* Mongolian spot

## Management[edit | edit source]

Cryotherapy

The management of a nevus depends on the specific diagnosis, however, the options for treatment generally include the following modalities:

### Observation[edit | edit source]

### Destruction[edit | edit source]

* Chemical peels
* Cryotherapy
* Dermabrasion
* Electrodessication
* Laser ablation

### Surgery[edit | edit source]

The decision to observe or treat a nevus may depend on a number of factors, including cosmetic concerns, irritative symptoms (e.g., pruritus), ulceration, infection, and concern for potential malignancy.[3]

## Syndromes[edit | edit source]

The term nevus is included in the names of multiple dermatologic syndromes:

* Basal cell nevus syndrome
* Blue rubber bleb nevus syndrome
* Dysplastic nevus syndrome
* Epidermal nevus syndrome
* Linear nevus sebaceous syndrome

## Etymology[edit | edit source]

A naevus may also be spelled nevus. The plural is nevi or naevi. The word is from nævus, Latin for "birthmark" and is correctly pronounced Nye-voos.

## See also[edit | edit source]

* Skin lesion

## References[edit | edit source]

1. ↑ James, William D.; Elston, Dirk; Treat, James R.; Rosenbach, Misha A.; Neuhaus, Isaac (2020). "28. Dermal and subcutaneous tumors". Andrews' Diseases of the Skin: Clinical Dermatology (13th ed.). Edinburgh: Elsevier. p. 594\. ISBN 978-0-323-54753-6. Archived from the original on 2022-10-05. Retrieved 2022-10-05.
2. ↑ Happle, Rudolf (1995). "What is a nevus? A proposed definition of a common medical term". Dermatology. 191 (1): 1–5. doi:10.1159/000246468. PMID 8589475.
3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 "Chapter 122. Benign Neoplasias and Hyperplasias of Melanocytes". Fitzpatrick's Dermatology in General Medicine. The McGraw-Hill Companies, Inc. 2012. ISBN 978-0-07-166904-7.
4. ↑ "Chapter 75. Hypomelanoses and Hypermelanoses". Fitzpatrick's Dermatology in General Medicine. The McGraw Hill Companies, Inc. 2012. ISBN 978-0-07-166904-7.
5. ↑ Baran, Robert; Berker, David A. R. de; Holzberg, Mark; Thomas, Luc (2012). Baran and Dawber's Diseases of the Nails and their Management. John Wiley & Sons. p. PT113. ISBN 9781118286708. Archived from the original on 2022-10-06. Retrieved 2022-10-05.
6. ↑ "Dysplastic (Atypical) Nevi". Melanocytic Lesions - Springer. 2014. doi:10.1007/978-1-4939-0891-2. ISBN 978-1-4939-0890-5.
7. ↑ 7.0 7.1 "Dermal melanocytosis". Melanocytic Lesions - Springer. 2014. doi:10.1007/978-1-4939-0891-2. ISBN 978-1-4939-0890-5.
8. ↑ 8.0 8.1 "Lentigo, Other Melanosis, and the Acquired Nevus". Melanocytic Lesions - Springer. 2014. doi:10.1007/978-1-4939-0891-2. ISBN 978-1-4939-0890-5.
9. ↑ 9.0 9.1 "Chapter 118. Benign Epithelial Tumors, Hamartomas, and Hyperplasias.". Fitzpatrick's Dermatology in General Medicine. The McGraw-Hill Companies, Inc. 2012. ISBN 978-0-07-166904-7.
10. ↑ 10.0 10.1 "Chapter 66. Dermal Hypertrophies and Benign Fibroblastic/Myofibroblastic Tumors.". Fitzpatrick's Dermatology in General Medicine. The McGraw-Hill Companies, Inc. 2012. ISBN 978-0-07-166904-7.
11. ↑ "Chapter 172. Vascular Malformations.". Fitzpatrick's Dermatology in General Medicine. The McGraw Hill Companies, Inc. 2012. ISBN 978-0-07-166904-7.
12. ↑ "Chapter 107. Neonatal, Pediatric, and Adolescent Dermatology". Fitzpatrick's Dermatology in General Medicine. The McGraw-Hill Companies, Inc. 2012. ISBN 978-0-07-166904-7.
13. ↑ "Oral Nevi". MedScape. Archived from the original on 6 October 2022. Retrieved 23 January 2018.
14. ↑ Buchner, A.; Merrell, P. W.; Carpenter, W. M. (2004). "Relative frequency of solitary melanocytic lesions of the oral mucosa". Journal of Oral Pathology and Medicine. 33 (9): 550–557. doi:10.1111/j.1600-0714.2004.00238.x. ISSN 0904-2512. PMID 15357676.
15. ↑ Rigel, Darrell S.; Russak, Julie; Friedman, Robert (2016-10-01). "The evolution of melanoma diagnosis: 25 years beyond the ABCDs". CA: A Cancer Journal for Clinicians. 60 (5): 301–316. doi:10.3322/caac.20074. ISSN 1542-4863. PMID 20671054.
16. ↑ Scope, Alon; Marchetti, Michael A.; Marghoob, Ashfaq A.; Dusza, Stephen W.; Geller, Alan C.; Satagopan, Jaya M.; Weinstock, Martin A.; Berwick, Marianne; Halpern, Allan C. (2016). "The study of nevi in children: Principles learned and implications for melanoma diagnosis". Journal of the American Academy of Dermatology. 75 (4): 813–823. doi:10.1016/j.jaad.2016.03.027. PMC 5030195. PMID 27320410.
17. ↑ "Ancillary Techniques in Diagnosing Melanocytic Lesions". Melanocytic Lesions - Springer. 2014. doi:10.1007/978-1-4939-0891-2. ISBN 978-1-4939-0890-5.

## External links[edit | edit source]

Classification|

* ICD-10: I78.1, D22
* ICD-9-CM: 448.1, 216.0-216.9
* MeSH: D009506

|

| Look up nevus in Wiktionary, the free dictionary.

|

* v
* t
* e

Diseases of the skin and appendages by morphology

Growths|

| Epidermal|

* Wart
* Callus
* Seborrheic keratosis
* Acrochordon
* Molluscum contagiosum
* Actinic keratosis
* Squamous-cell carcinoma
* Basal-cell carcinoma
* Merkel-cell carcinoma
* Nevus sebaceous
* Trichoepithelioma

|

Pigmented|

* Freckles
* Lentigo
* Melasma
* Nevus
* Melanoma

Dermal and
subcutaneous|

* Epidermal inclusion cyst
* Hemangioma
* Dermatofibroma (benign fibrous histiocytoma)
* Keloid
* Lipoma
* Neurofibroma
* Xanthoma
* Kaposi's sarcoma
* Infantile digital fibromatosis
* Granular cell tumor
* Leiomyoma
* Lymphangioma circumscriptum
* Myxoid cyst

Rashes|

| With
epidermal
involvement|

| Eczematous|

* Contact dermatitis
* Atopic dermatitis
* Seborrheic dermatitis
* Stasis dermatitis
* Lichen simplex chronicus
* Darier's disease
* Glucagonoma syndrome
* Langerhans cell histiocytosis
* Lichen sclerosus
* Pemphigus foliaceus
* Wiskott–Aldrich syndrome
* Zinc deficiency

|

Scaling|

* Psoriasis
* Tinea (Corporis
* Cruris
* Pedis
* Manuum
* Faciei)
* Pityriasis rosea
* Secondary syphilis
* Mycosis fungoides
* Systemic lupus erythematosus
* Pityriasis rubra pilaris
* Parapsoriasis
* Ichthyosis

Blistering|

* Herpes simplex
* Herpes zoster
* Varicella
* Bullous impetigo
* Acute contact dermatitis
* Pemphigus vulgaris
* Bullous pemphigoid
* Dermatitis herpetiformis
* Porphyria cutanea tarda
* Epidermolysis bullosa simplex

Papular|

* Scabies
* Insect bite reactions
* Lichen planus
* Miliaria
* Keratosis pilaris
* Lichen spinulosus
* Transient acantholytic dermatosis
* Lichen nitidus
* Pityriasis lichenoides et varioliformis acuta

Pustular|

* Acne vulgaris
* Acne rosacea
* Folliculitis
* Impetigo
* Candidiasis
* Gonococcemia
* Dermatophyte
* Coccidioidomycosis
* Subcorneal pustular dermatosis

Hypopigmented|

* Tinea versicolor
* Vitiligo
* Pityriasis alba
* Postinflammatory hyperpigmentation
* Tuberous sclerosis
* Idiopathic guttate hypomelanosis
* Leprosy
* Hypopigmented mycosis fungoides

Without
epidermal
involvement|

| Red|

| Blanchable
Erythema|

| Generalized|

* Drug eruptions
* Viral exanthems
* Toxic erythema
* Systemic lupus erythematosus

|

Localized|

* Cellulitis
* Abscess
* Boil
* Erythema nodosum
* Carcinoid syndrome
* Fixed drug eruption

Specialized|

* Urticaria
* Erythema (Multiforme
* Migrans
* Gyratum repens
* Annulare centrifugum
* Ab igne)

Nonblanchable
Purpura|

| Macular|

* Thrombocytopenic purpura
* Actinic/solar purpura

|

Papular|

* Disseminated intravascular coagulation
* Vasculitis

Indurated|

* Scleroderma/morphea
* Granuloma annulare
* Lichen sclerosis et atrophicus
* Necrobiosis lipoidica

Miscellaneous
disorders|

| Ulcers|

|

Hair|

* Telogen effluvium
* Androgenic alopecia
* Alopecia areata
* Systemic lupus erythematosus
* Tinea capitis
* Loose anagen syndrome
* Lichen planopilaris
* Folliculitis decalvans
* Acne keloidalis nuchae

Nail|

* Onychomycosis
* Psoriasis
* Paronychia
* Ingrown nail

Mucous
membrane|

* Aphthous stomatitis
* Oral candidiasis
* Lichen planus
* Leukoplakia
* Pemphigus vulgaris
* Mucous membrane pemphigoid
* Cicatricial pemphigoid
* Herpesvirus
* Coxsackievirus
* Syphilis
* Systemic histoplasmosis
* Squamous-cell carcinoma

* v
* t
* e

Skin cancer of nevi and melanomas

Melanoma|

* Mucosal melanoma
* Superficial spreading melanoma
* Nodular melanoma
* lentigo
* Lentigo maligna/Lentigo maligna melanoma
* Acral lentiginous melanoma
* Amelanotic melanoma
* Desmoplastic melanoma
* Melanoma with features of a Spitz nevus
* Melanoma with small nevus-like cells
* Polypoid melanoma
* Nevoid melanoma
* Melanocytic tumors of uncertain malignant potential

Nevus/
melanocytic nevus|

* Nevus of Ito/Nevus of Ota
* Spitz nevus
* Pigmented spindle cell nevus
* Halo nevus
* Pseudomelanoma

* Blue nevus
* of Jadassohn–Tièche
* Cellular
* Epithelioid
* Deep penetrating
* Amelanotic
* Malignant

* Congenital melanocytic nevus (Giant
* Medium-sized
* Small-sized)

* Balloon cell nevus
* Dysplastic nevus/Dysplastic nevus syndrome

* Acral nevus
* Becker's nevus
* Benign melanocytic nevus
* Nevus spilus

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