Epidermal nevus (overview) D23.L

The term "epidermal nevus" as hamartoma of the skin, points to v. Baerensprung, who first used the term"nevus unius lateris" (cited in Su et al.) for a systematized verrucous nevus in 1863.

Congenital or appearing in the first years of life, to be interpreted as cutaneous mosaic, inflammatory or non-inflammatory, reddish-brown or dirty-brown, soft-papillomatous or wart-like-hard malformations of the epidermis (often with dermal component) or its appendages, which, apart from CHILD syndrome, manifest in the Blaschko lines or as other cutaneous mosaics.

Various epidermal hamartomas (epidermal nevi) should be considered as monitorial signs of complex syndromic malformations.

The following distinctions can be made:

• Simple (non-organoid) epidermal hamartomas (nevi) (affecting only the epidermis)
• Compound "organoid" epidermal nevi (affecting epidermis and skin appendages)
• Epidermal nevi as monitorial signs for syndromes.
  • Epidermal hamartomas (nevi):
    • Papillomatous (soft) epidermal nevus (postzygotic mutations in FGFR3,PIK3CA, KRAS genes)
    • Verrucous (hard) epidermal nevus (nevus verrucosus
      )Special form: nevus
      verrucosus unius lateralis
    • ILVEN
    • Epidermolytic epidermal nevus (minus variant of keratosis plamoplantaris diffusa with mutations in keratin1)
    • CHILD syndrome
    • Corniculatus nevus
    • Segmental M. Darier
    • Segmental M. Hailey-Hailey ( Pemphigus chronicus benignus familiaris)
    • Linear porokeratosis (linear manifestation of disseminated superficial actinic porokeratosis)
    • Linear manifestation of plaque-like porokeratosis mibelli
  • Organoid (compound) epidermal nevi:
    • Nevussebaceus (proven mutations in the HRAS gene)
    • Nevus comedonicus
    • Porokeratotic eccrine ostium nevus (PEODDN)
    • Hamartoma, eccrine
    • Becker nevus
    • Hair ne vus (see also curlyhair nevus)
    • Munro's naevus.
  • Epidermal nevi as monitoring signs for syndromes.
    • Schimmelpenning-Feuerstein-Mims syndrome
    • Proteus syndrome
    • Child syndrome
    • Phakomatosis pigmentokeratotica
    • Nevus comedonicus syndrome
    • Angora hair nevus syndrome
    • Becker nevus syndrome.

The incidence is estimated at 1:1000 children. In a larger study with 131 nevi occurring up to 14 years of age, 80% of the nevi were present at birth (Rogers M et al. 1989).

From a histopathological point of view (cited in Su 1982) the following classification results:

1. acrokeratosis verruciformis-like
2. Epidermolytic-hyperkeratotic
3. Seborrheic keratosis-like
4. Psoriasiform (eczematoid) - inflammatory linear verrucous epidermal nevus = ILVEN
5. Wart-like (verrucous)
6. Porokeratosis-like
7. Acantholytic
8. Comedon-like

1. The A et al (2014) Linear non-epidermolytic verrucous epidermal nevus. Indian Pediatr 51:591
2. Fan YM et al (2014) An atypical variant of phacomatosis pigmentokeratotica: verrucous epidermal nevus, speckled lentiginous nevus, and pointed nevus associated with scoliosis. Int J Dermatol 53: 619-621
3. Kruse LL et al (2015) Differential Diagnosis of Linear Eruptions in Children. Pediatr Ann.44:e194-e198
4. Su WP(1082)Histopathological varieties of epidermal nevus. A study of 160 cases. At J Dermatopathol 4:161-170
5. Rogers M et al (1989) Epidermal nevi and the epidermal nevus syndrome.
   A review of 131 cases. J Am Acad Dermatol 20:476-88.
6. Waghmare RS et al. (2013) Inflammatory linear verrucous epidermal nevus. J Assoc Physicians India 61:431-432