The incidence of congenital nevus is approximately 1 in 100 live births [1] [2] and it may be observed by parents of affected infants/ children or may be detected in adolescence or even in adulthood. It can occur on any part of the body and is defined as a "giant melanocytic nevus" when it reaches a minimum diameter of 20 cm [3].

Congenital nevus in children and adolescents appears as a skin lesion with perifollicular hypopigmentation, irregular edges with projections or variegated pigmentation within the nevus [4]. Compared to its acquired version, a congenital melanocytic nevus is large, asymmetrical and comma shaped and is located on the flexor surfaces of the extremities [5]. In a majority of the cases, it is asymptomatic. It may be associated with infantile hemangiomas [6].

A giant congenital melanocytic nevus is also rare but is clinically important as it can be associated with malignant melanoma and neurocutaneous melanosis. In addition, it can cause a psychological impact on the patients and their families due to its ungainly appearance [7] [8] with consequent disfigurement, especially when it is present on the face [9]. It is a brown colored skin lesion with well-defined edges and hypertrichosis [3]. It usually occurs on the torso but can also be found on the extremities and head [8] [10] [11] and often involves multiple segments of the body. It is mostly asymptomatic but patients may show the signs of pruritus.

• Asymptomatic

  In a majority of the cases, it is asymptomatic. It may be associated with infantile hemangiomas. [symptoma.com]

  Frieden et al found that 30% of patients with a LCMN had asymptomatic NCM.5 Routine MRIs will likely pick up an increasing number of cases of asymptomatic NCM in the context of a LCMN or multiple smaller CMN. [the-dermatologist.com]

  Giant congenital melanocytic nevi: brain magnetic resonance findings in neurologically asymptomatic children. J Am Acad Dermatol. 1994;31:423-9. [ Links ] 60. Chung C, Forte A, Narayan D, Persing J. Giant nevi: a review. [scielo.br]

  Asymptomatic neurocutaneous melanocytosis in patients with large congenital melanocytic nevi: a study of cases from an Internet-based registry. Journal of the American Academy of Dermatology 53, 959-65. Ahmed, I., Tope, W. D., Young, T. [rarediseases.org]

• Epilepsy

  Neurological involvement, such as leptomeningeal melanocytosis (see this term), epilepsy, hydrocephalus and tethered spinal cord has been observed. [orpha.net]

  Giant hairy nevi on the scalp and neck may be associated with leptomeningealmelanocytosis and neurologic disorders that include neurofibromatosis, epilepsy or focal neurologic abnormalities. [ispub.com]

  The pigment cells in the brain or spine cannot currently be treated themselves, but the epilepsy that sometimes occurs in NCM can respond to conventional medication and surgical approaches, as can a tethered spinal cord or cysts. [naevusglobal.org]

• Lymphedema

  Q82.5 ICD-10-CM Codes Adjacent To Q82.5 Q81.1 Epidermolysis bullosa letalis Q81.2 Epidermolysis bullosa dystrophica Q81.8 Other epidermolysis bullosa Q81.9 Epidermolysis bullosa, unspecified Q82 Other congenital malformations of skin Q82.0 Hereditary lymphedema [icd10data.com]

• Hyperpigmentation

  More peripherally, there was macular hyperpigmentation of the skin with superimposed darker brown macules of various sizes ( Figure 3 ). [jamanetwork.com]

  Becker’s nevus – First noted by Samuel William Becker in 1948, this is a benign brown hyperpigmentation with hairy portions located mainly on the upper arm or back and chest. The borders of the nevus are irregular. [houstoncraniofacial.com]

  The clinical presentation often changes with age: a hairless, pale brown, flat lesion at birth may evolve to have hyperpigmentation, hairgrowht, ulcerations and a verrucous texture. [plastischechirurgiegent.be]

  […] and peripheral leukoderma Click here to view Dermoscopy of the CMN in the area of black hyperpigmentation showed typical thin and thick pigment network with coarse terminal hairs. [ijdvl.com]

• Cafe-Au-Lait Spots

  Mongolian spot – Typically seen in Asians and Native Americans, this lesion is like cafe au lait spots but bluish in color. Sometimes it is mistaken for a bruise. [houstoncraniofacial.com]

  I'm not sure if it's a cafe au lait spot or a mole. She also has tiny skin tag on her belly. I'm fearing it's something more serious like neurofibr … read more Dr. [justanswer.com]

  Prevalence of congenital-nevus-like, nevi spili and cafe au lait spots. Arch Dermatol, 121 (1985), pp. 766-769 [6.] M.L. Williams, R. Pennella. Melanoa, melanocytic nevi, and other melanoma risk factors in children. [analesdepediatria.org]

  […] individuals who, in addition to GCMN, present with diffuse lipomatosis, hypertrophy of cranial bones, atrophy of limbs, skeletal asymmetries involving hyper-or hypoplasia of soft tissues, scoliosis, urinary tract anomalies, capillary vascular malformations, cafe-au-lait [ncbi.nlm.nih.gov]

• Erythema

  (Dorland, 27th ed) A vascular malformation of developmental origin characterized pathologically by ectasia of superficial dermal capillaries, and clinically by persistent macular erythema. [icd10data.com]

  (see note below) especially in a person with personal or family history of melanoma); or Skin lesions are causing symptoms (e.g., bleeding, burning, intense itching, or irritation); or The lesion has evidence of inflammation (e.g., edema, erythema, or [aetna.com]

• Skin Disease

  Sheila Fallon Friedlander said at the Women’s & Pediatric Dermatology Seminar sponsored by Skin Disease Education Foundation (SDEF). "Here’s our new definition that you’re going to be seeing in the literature," said Dr. [pediatricnews.com]

  Photo Credit Gracia Lam Personal Health A Little-Known Skin Disease That Can Disrupt People’s Sex Lives Patients deal with pain and itching and often encounter medical ignorance and mistreatment until affected tissues become irreparably scarred. [nytimes.com]

• Macula

  Classification Small congenital nevi that are less than 1.5 cm2 tend to be irregularly shaped maculae or papules ( skin lesions ) with a tan to brown color. These will become darker as the child ages and goes through puberty. [houstoncraniofacial.com]

• Confusion

  Sometimes people get confused about the difference between congenital and hereditary. Hereditary means you get if from your parents and/or pass it along to your kids. There is no evidence that congenital nevi are hereditary. [nevus.org]

  Spitz nevus – Often associated or confused with melanoma, this lesion is noted as a solitary round raised bump with red or dark pigmentation located on the face. [houstoncraniofacial.com]

  Lastly, we believe that the practice of referring to a smaller lesion as a nevus spilus and a larger lesion as a speckled lentiginous nevus simply adds to the confusion. [jamanetwork.com]

A congenital nevus can be identified as such based on either history, medical records or photographic evidence of its presence since birth. The gold standard test, however, is a biopsy of the suspected lesion.

Magnetic resonance imaging (MRI) is indicated, especially if a congenital nevus is detected in a posterior region in an infant less than 4 months of age or if the infant has multiple satellite lesions [12] as it could be associated with neurocutaneous melanosis. MRI and scintigraphy can also help to detect rare cases of congenital nevi involving the bones or the maxillary sinus.

Dermoscopy is an excellent tool for evaluating the nevus and will demonstrate globular or reticular or a mixed pattern. The patterns vary with age and location - young children often have a globular pattern while those above 12 years of age have a reticular pattern [13].

Histological studies are essential due to the risk of malignant melanoma. A congenital nevus can be differentiated from an acquired nevus due to the following characteristics that are seen under a microscope [14] [15] [16]:

• It involves deep appendages and neurovascular tissues such as hair follicles, sebaceous glands, arrector pili muscles, and blood vessel walls compared to acquired nevus which does not involve dermal appendages and is restricted to the upper layers of the dermis.
• The nevus extends to the deeper parts of the dermis and involves subcutaneous fat.
• The nevus cells extend between the dermal collagen bundles and the sub-epidermal zone in a nevus has a paucity of nevus cells.

Treatment must weigh the risk of malignancy, psychological distress to parents and child, and potential morbidities of excision. Excision of every nevus is neither applicable nor practical. [ncbi.nlm.nih.gov]

Treatment options for giant congenital naevi. Clin Exp Dermatol. 2000;25:7-11. [ Links ] 94. Marghoob AA, Schoenbach SP, Kopf AW, Orlow SJ, Nossa R, Bart RS. [scielo.br]

No treatment is necessary for these lesions. However, if the patient desires treatment, laser is an option to be considered (Fig 1). [journals.lww.com]

Treatment Options Treatment options are summarized in Table I. Table I. [clinicaladvisor.com]

The clinical implications and known information about the prognosis of intradermal malignant melanomas are discussed. [ncbi.nlm.nih.gov]

What is the Prognosis of Congenital Melanocytic Nevus? (Outcomes/Resolutions) In a majority of cases, the prognosis of Congenital Melanocytic Nevus is excellent, since it is a benign condition. [dovemed.com]

Prognosis Small or medium congenital melanocytic naevi carry a good prognosis with a low risk of transformation to melanoma. [patient.info]

The overlapping presentation suggests a common etiologic link between neurofibromatosis and large congenital nevi and the possibility that neurofibromatosis increases the risk of melanoma with large congenital nevi. [ncbi.nlm.nih.gov]

Etiology LCMN is a neurocristopathy (a disorder of the development of the embryonic neural crest) but its etiology is unknown. Diagnostic methods The diagnosis is clinical. [orpha.net]

The presence of melanocytic antibodies and lymphocytic infiltrates in vitiligo indicates probable autoimmune etiology, which is a widely accepted hypothesis. [6] Vitiligo can occur as vitiligo vulgaris, segmental vitiligo or vitiligo acrofacialis. [jdrntruhs.org]

Epidemiology 6: Susceptibility Genes DOI: Published April 2006 Proc Amer Assoc Cancer Res, Volume 47, 2006 Abstract 2335 Most melanocytic nevi develop on sun-exposed skin during childhood and adolescence and commonly harbor BRAF mutations or, less frequently [cancerres.aacrjournals.org]

Summary Epidemiology LCMN has a prevalence of about 1/20,000, while GCMN is estimated to occur in 1/50,000 to 1/500,000 births, becoming increasingly rare as more body surface is implicated. [orpha.net]

Epidemiology Approximately 1-3% of all newborns have congenital pigmented naevi. [ 2 ] Presentation The naevus may be noted at birth or shortly afterwards. [patient.info]

Pathophysiology Neural crest Melanocyte s and their precursors with disrupted migration IV. [fpnotebook.com]

Pathophysiology Little is known about the pathophysiology of congenital melanocytic nevi. [clinicaladvisor.com]

The Pigmentary System: Physiology and Pathophysiology New York, NY1998;958- 66 Google Scholar 29. Sato SKato HHidano A Divided nevus spilus and divided form of spotted grouped pigmented nevus. [jamanetwork.com]

Many are surgically removed for aesthetics and relief of psychosocial burden, but larger ones are also excised for prevention of cancer, although the benefit is impossible to assess for any individual patient. [en.wikipedia.org]

Prevention To prevent melanoma in all people, but particularly those with large congenital pigmented naevi, advise: Reducing ultraviolet (UV) light exposure. Reducing peak sunlight exposure during most intense sun periods. [patient.info]

Avoiding smoking prevents premature aging. But the number-one way to keep skin gorgeous is to stay out of the sun and away from tanning beds. The suns radiation causes skin damage, including wrinkles, age spots and skin cancer. [sharecare.com]

Some of these moles are removed for cosmetic reasons, and giant nevi are often excised to prevent cancer, as 5 to 15 percent of giant congenital melanocytic nevi may develop into melanoma. [ozarkderm.com]

1. Walton RG, Jacobs AH, Cox AJ. Pigmented lesions in newborn infants. Br J Dermatol. 1976;95:389–396.
2. Castilla EE, da Graça Dutra M, Orioli-Parreiras IM. Epidemiology of congenital pigmented naevi: I. Incidence rates and relative frequencies. Br J Dermatol. 1981;104:307–315.
3. Leite Viana AC, Gontijo B, Bittencourt FV.Giant congenital melanocytic nevus. An Bras Dermatol. 2013 Nov-Dec; 88(6): 863–878.
4. Tcheung WJ, Bellet JS, Prose NS, Cyr DD, Nelson KC. Clinical and Dermoscopic Features of 88 Scalp Nevi in 39 Children. Br J Dermatol. 2011 Jul;165(1):137-43.
5. Chuah SY, Tsilika K, Chiaverini C, et al. Dermoscopic features of congenital acral melanocytic nevi in children: a prospective comparative and follow-up study. Br J Dermatol. 2015; 172(1): 88-93.
6. Wu PA, Mancini AJ, Marghoob AA, Frieden IJ. Simultaneous occurrence of infantile hemangioma and congenital melanocytic nevus: Coincidence or real association?. J Am Acad Dermatol. 2008 Feb. 58(2 Suppl): S16-22.
7. Kovalyshyn I, Braun R, Marghoob A. Congenital melanocytic naevi. Australas J Dermatol. 2009;50:231–240.
8. Marghoob AA, Bittencourt FV, Kopf AW, Bart RS. Large congenital melanocytic nevi. Curr Probl Dermatol. 2000;12:146–152.
9. Price H, Schaffer J. Congenital melanocytic nevi-when to worry and how to treat: Facts and controversies. Clin Dermatol. 2010;28:293–302.
10. Bittencourt F, Marghoob A, Kopf A, Koenig K, Bart R. Large congenital melanocytic nevi and the risk for development of malignant melanoma and neurocutaneous melanocytosis. Pediatrics. 2000;106:736–741.
11. Arneja JS, Gosain AK. Giant congenital melanocytic nevi of the trunk and an algorithm for treatment. J Craniofac Surg. 2005;16:886–893.
12. Lovett A, Maari C, Decarie JC, et al. Large congenital melanocytic nevi and neurocutaneous melanocytosis: one pediatric center's experience. J Am Acad Dermatol. 2009 Nov;61(5):766-74.
13. Changchien L, Dusza SW, Agero AL, et al. Age- and site-specific variation in the dermoscopic patterns of congenital melanocytic nevi: an aid to accurate classification and assessment of melanocytic nevi. Arch Dermatol. 2007 Aug; 143(8):1007-14.
14. Mark GJ, Mihm MC, Liteplo MG, Reed RJ, Clark WH. Congenital melanocytic nevi of the small and garment type. Clinical, histologic, and ultrastructural studies. Hum Pathol. 1973;4:395–418.
15. Rhodes AR, Silverman RA, Harrist TJ, Melski JW. A histologic comparison of congenital and acquired nevomelanocytic nevi. Arch Dermatol. 1985 Oct; 121(10):1266-73.
16. Everett MA. Histopathology of congenital pigmented nevi. Am J Dermatopathol. 1989 Feb; 11(1):11-2.