Congenital Melanocytic Nevus

Aka: Congenital Melanocytic Nevus, Congenital Melanocytic Nevi, Garment Nevi, Giant Congenital Nevi, Giant Hairy Nevi, Bathing Trunk Nevi, Congenital Nevus, Congenital Nevi

advertisement

II. Epidemiology

  1. Prevalence: Up to 2-5% of newborns

III. Pathophysiology

  1. Neural crest Melanocytes and their precursors with disrupted migration

IV. Signs

  1. Brown to black lesions that are typically flat
    1. Can be elevated
    2. May thicken as children get older
  2. Size can vary from a few millimeters to several centimeters
    1. In some cases, may be very large, involving an entire region of the body
    2. Lesions increase in size with age
      1. Head lesions double in size with age
      2. Extremity and trunk lesions triple in size with age
  3. Hair is variably present
  4. Typically with uniform pigmentation
  5. Broad Distribution (trunk, extremiities, face)

V. Types: Speckled Lentiginous Nevus (Nevus Spilus)

  1. Variant of Congenital Nevi
    1. Hairless round to irregularly shaped brown nevus
    2. Larger nevus contains 1-3 mm dots of dark brown pigmentation (may be elevated)
    3. Diameter ranges from 1-20 cm
  2. Malignant transformation is uncommon but can occur
    1. Size of lesion directs management - follow the same protocols for Congenital Nevi based on size below
    2. Observe and biopsy or excise lesions if atypical

VI. Lab: Histology

  1. Localized to the lower Dermis

VII. Differential Diagnosis

  1. Cafe-Au-Lait Spots

VIII. Complications: Melanoma

  1. Small Congenital Nevi <1.5 cm (adult size) rarely progress to Melanoma
  2. Medium size lesions may develop Melanoma in up to 0.7% of cases
  3. Giant Congenital Nevi >20 cm (adult size) carry up to a 7% lifetime risk of Melanoma
    1. Half of Melanomas in Giant Congenital Nevi occur by age 3-5 years

IX. Management

  1. General
    1. Carefully document lesion locations and size
      1. Consider images with a ruler (or labeled diagrams)
  2. Large Congenital Melanocytic Nevi (Giant Congenital Nevi)
    1. Criteria
      1. Garment Nevi or Giant Congenital Nevi: >14 cm in infants (>20 cm in adults)
      2. Large Congenital Nevi: >12 cm head or >7 cm elsewhere in infants (>20 cm adults)
    2. Precautions
      1. As noted above, Melanoma development in Giant Congenital Nevi occurs before age 3-5 years in 50% of cases
      2. Excise these lesions as infants or young children (before age 3-5 years)
        1. However, lesion excision does not completely eliminate the malignancy risk
      3. Observation may miss transformation due to depth of nevus
    3. Protocol
      1. Excise lesion as soon as possible (or currettage during the first 2 weeks of life)
      2. Close observation for recurrence (excision does not eliminate risk completely)
  3. Medium Congenital Melanocytic Nevi
    1. Criteria: 0.5 to 7 cm in infants (1.5 to 20 cm in adults)
    2. Protocol
      1. Close observation by dermatology
      2. Consider Punch Biopsy for risk stratification
        1. Deeper dermal lesions may elude early detection of malignant transformation despite observation
  4. Small Congenital Melanocytic Nevi
    1. Criteria: <0.5 cm in infants (<1.5 cm in adults)
    2. Low malignant potential (especially pre-Puberty)
    3. Protocol
      1. Close observation by primary provider
      2. Refer lesions with change in color, texture, size, bleeding or pain
      3. If excised, it is safe to wait until after Puberty

X. References

  1. Habif (2003) Clinical Dermatology, 4th ed.. Mosby, p. 773-813
  2. Berg (2003) Melanoma Res 13:441-5 [PubMed]
  3. Krengel (2006) Br J Dermatol 155:1-8 [PubMed]
  4. McLaughlin (2008) Am Fam Physician 77:56-60 [PubMed]
  5. Snyder (2024) Am Fam Physician 109(3): 212-6 [PubMed]

Images: Related links to external sites (from Bing)

These images are a random sampling from a Bing search on the term "Congenital Melanocytic Nevus." Click on the image (or right click) to open the source website in a new browser window. Search Bing for all related images

Related Studies

Ontology: Congenital melanocytic nevus (C1318558)

Definition (NCI) A melanocytic nevus that is present at birth. It may present as a small macular, papular, or plaque-like lesion or as a large brown to black hairy skin lesion.
Concepts Neoplastic Process (T191)
SnomedCT 254203006, 84953004, 400151006, 398696001, 398943008
English Congen melanocytic naevus skin, Congen melanocytic nevus skin, Congen pigmented naevus skin, Congen pigmented nevus skin, Congenital Nevus of the Skin, Congenital Nevus of Skin, Congenital Skin Nevus, Congenital Melanocytic Nevus, congenital pigmented naevus, congenital melanocytic naevus, congenital melanocytic nevus, nevus pigmented congenital, congenital pigmented nevus, Congenital melanocytic nevus of skin (disorder), Congenital melanocytic nevus (disorder), Congenital Melanocytic Nevi, Congenital Pigmented Melanocytic Nevus, Congenital melanocytic naevus, Congenital melanocytic naevus of skin, Congenital melanocytic nevus of skin, Congenital pigmented naevus, Congenital pigmented naevus of skin, Congenital pigmented nevus, Congenital pigmented nevus of skin, Congenital dermal melanocytic naevus, Congenital dermal melanocytic nevus, Congenital melanocytic nevus (morphologic abnormality), Congenital pigmented melanocytic naevus of skin, Congenital pigmented melanocytic naevus, Congenital pigmented melanocytic nevus (disorder), Congenital pigmented melanocytic nevus of skin (disorder), Congenital pigmented melanocytic nevus of skin, Congenital pigmented melanocytic nevus, Congenital melanocytic nevus, Congenital melanocytic nevus, NOS, Congenital Melanocytic Nevus of Skin, Congenital Melanocytic Nevus of the Skin, Congenital Pigmented Nevus of Skin, Congenital Pigmented Nevus of the Skin, Congenital Pigmented Skin Nevus
Czech Vrozený melanocytový névus, Vrozený melanocytární névus
Dutch congenitale melanocytische naevus
French Naevus mélanocytaire congénital
German kongenitaler melanozytaerer Naevus
Hungarian Veleszületett melanocytás naevus
Italian Nevo melanocitico congenito
Japanese 先天性メラノサイト性母斑, ｾﾝﾃﾝｾｲﾒﾗﾉｻｲﾄｾｲﾎﾞﾊﾝ
Portuguese Nevo melanocítico congénito
Spanish Nevus melanocítico congénito, nevo melanocítico congénito (trastorno), nevo congénito melanocítico pigmentado (trastorno), nevo congénito melanocítico pigmentado, nevo congénito pigmentado melanocítico de piel, nevo melanocítico congénito (anomalía morfológica), nevo melanocítico congénito, nevus congénito pigmentado melanocítico de piel (trastorno), nevus congénito pigmentado melanocítico de piel, nevus melanocítico congénito
Derived from the NIH UMLS (Unified Medical Language System)

Related Topics in Pediatrics

advertisement

2025 Family Practice Notebook, LLC. Terms | Privacy | About | Site Map | Newsletter | Blog

Footer Site Logo