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Congenital Nevus

Congenital Naevus

Congenital nevus is a rare dermatological lesion that is present at birth on the acral volar regions of the body and has an unsightly appearance. It is called a giant congenital melanocytic nevus when it attains a diameter of 20 cm. Confirmation of the diagnosis requires a histological evaluation of a biopsy specimen.


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.

Loss of Hair
  • Occasionally, congenital melanocytic nevus are completely hairless, even ones that occur in the scalp, or can have patchy hair loss or hairs without pigment (grey or white hair).[naevusglobal.org]
Soft Tissue Swelling
  • An X-ray of her skull and ultrasonography revealed soft tissue swelling in the left temporofrontoparietal region.[jmedicalcasereports.com]
Foul Smelling Discharge
  • Upon applying pressure, there was a scanty, yellowish, non-foul-smelling discharge that was occasionally blood-stained and was associated with intense itching without any pain. Her sleep, appetite, bowel, and bladder were unaltered.[jmedicalcasereports.com]
  • It was non-pulsatile with no evidence of impulse on coughing. The regional lymph nodes were not palpable. Numerous hairy nevi were present over the scalp, trunk, and limbs. Figure 1 Gross appearance of the lesion.[jmedicalcasereports.com]
Failure to Thrive
  • GROSS APPEARANCE/ CLINICAL VARIANTS CHARACTERIZATION GENERAL NEUROCUTANEOUS MELANOSIS Signs Hydrocephalus Macrocephaly Increasing head circumference Bulging fontanelle Seizures Developmental delay Symptoms Headache Vomiting Failure to thrive Weakness[thedoctorsdoctor.com]
  • Within the past three months, swelling had progressed from the hairline to just above the left brow, leading to unilateral mechanical ptosis.[jmedicalcasereports.com]
Flexion Contracture
  • The boy also had flexion contractures of the finger joints of the left hand and boggy swelling in the left axilla with inability to move his shoulder joint.[dx.doi.org]
Subcutaneous Nodule
  • The original tumor was a large dermal/subcutaneous nodule composed of very well-differentiated cells reminiscent of type B nevomelanocytes. The metastasis displayed similar histology.[ncbi.nlm.nih.gov]
Localized Scleroderma
  • We describe a rare case of a sclerotic hypopigmented large congenital melanocytic nevus in which a localized scleroderma-like reaction process of regression seemed to have started in utero and progressed throughout early childhood. 2016 Wiley Periodicals[ncbi.nlm.nih.gov]
Focal Neurologic Deficit
  • The association of the pigmented lesion with a focal neurological deficit is pathognomonic for neurocutaneous melanosis complicated by a leptomeningeal melanoma.[ncbi.nlm.nih.gov]
Spinal Cord Syndrome
  • Large congenital nevi also are associated with increased risks for liposarcoma, rhabdomyosarcoma, and (in some body locations) tethered spinal cord syndrome.[pediatricnews.com]
Focal Seizure
  • The subset of patients with a discrete intra-cranial mass become symptomatic when they are older (mean age, 12.8 years; age range, birth to 65 years) and are more likely to develop focal seizures, localized sensorimotor deficits, difficulties with speech[jmedicalcasereports.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.
Mediastinal Mass
  • We report a case of an anterior mediastinal mass in a patient with a giant congenital nevus and neurofibromatosis type I.[ncbi.nlm.nih.gov]
Anterior Mediastinal Mass
  • We report a case of an anterior mediastinal mass in a patient with a giant congenital nevus and neurofibromatosis type I.[ncbi.nlm.nih.gov]
Cortical Tubers
  • The present case pointed toward a definite diagnosis of tuberous sclerosis complex because of two major features: calcified subependymal nodules within the body of the lateral ventricles and cortical tubers as confirmed by MRI.[jmedicalcasereports.com]


  • Dermabrasion is one approach to the treatment of treating giant melanocytic congenital nevi. Treatment is recommended to reduce the risk of spontaneous malignant transformation of giant nevi into malignant melanomas that usually occur in childhood.[ncbi.nlm.nih.gov]
  • 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]
  • The most recent retrospective studies have suggested the risk of melanoma develops in 3 to 9 percent without surgical treatment and less than 1 percent with surgical treatment.[plastischechirurgiegent.be]
  • A proper treatment plan needs to be discussed with parents after examining the lesion and reviewing the risk of malignancy and surgical intervention. Afterwards, parents can select a desired treatment plan.[drtotonchi.com]


  • […] transformation of a giant congenital melanocytic nevus (GCMN), although rare, should be considered, especially in proliferative lesions that have nodules on their surface, as they can clinically and histologically mimic melanoma and generally have a poor prognosis[ncbi.nlm.nih.gov]
  • 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]
  • We discuss possible etiologies.[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]


  • 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]
  • Epidemiology Prevalence : Up to 2% of newborns III. Pathophysiology Neural crest Melanocyte s and their precursors with disrupted migration IV.[fpnotebook.com]
Sex distribution
Age distribution


  • 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]


  • 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]
  • 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]
  • Causes: There is no known cause, and therefore no way to prevent these birthmarks. Possible complications: There is risk of skin cancer developing in the nevus. The risk is higher during the time when the body is maturing.[madisonadoption.org]
  • 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]



  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.

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Last updated: 2019-06-28 11:57