AUTHOR AND EDITOR INFORMATION

Section 1 of 8  

• Authors and Editors
• Introduction
• Clinical Presentation
• Differential Diagnosis
• Management And Treatment
• Malignant Potential
• Multimedia
• References

INTRODUCTION

Section 2 of 8  

• Authors and Editors
• Introduction
• Clinical Presentation
• Differential Diagnosis
• Management And Treatment
• Malignant Potential
• Multimedia
• References

The congenital nevomelanocytic nevus (CNN), known commonly as the congenital hairy nevus, denotes a pigmented surface lesion present at birth.

• Nevomelanocytes, derivatives of melanoblasts, compose the cellular format of the neoplasm.
• CNN are characterized as small ( <1.5 cm in diameter), medium (1.5 cm-19.5 cm), and large or giant (>20 cm in adolescents and adults or comprising 5% of the body surface area or greater in infants, children, and preadolescents).

The potential for large congenital hairy nevi to become malignant is significant and is an important consideration in the treatment and management of this entity.

• A recent study at the University of Pennsylvania Medical Center reported a 5.7% cumulative 5-year risk of developing a cutaneous melanoma in patients with large or giant CNN.
• Other studies reveal a melanoma risk in patients with large CNN of 8.5% during the first 15 years of life.

The risk of malignant melanoma transformation is controversial in medium (1.5-19.9 cm in diameter) CNN.

• The results of a recent short-term follow-up study, from the New York University School of Medicine, does not support the view that there is a clinically significantly increased risk for malignant melanoma arising in medium CNN.
• Other studies conclude patients with CNN of any size may have a lifetime melanoma risk of at least 5%.
• CNN are present in 1% of newborns.
• Most congenital nevi are smaller than 3-4 cm in diameter, while very large congenital nevi are present in 1 per 20,000 to 1 per 500,000 newborns.
• Very large congenital nevi account for less than 0.1% of cutaneous melanomas, whereas small varieties of congenital nevi may account for 15% of cutaneous melanomas.

Management and treatment of patients with CNN depends on size, location, and propensity for malignant transformation.

• Aesthetic considerations are important.
• Surgical treatment of giant or large CNN is addressed at age 6 months.
• Procedures used in surgical treatment include serial excision and reconstruction with skin grafting, tissue expansion, and local rotation flaps.
• Adjunctive treatment options include chemical peels, dermabrasion, and laser surgeries.
• Cultured epidermal autographs have been used successfully for select cases.
• Removal of smaller lesions is delayed until adolescence.
• Management of small lesions includes close monitoring with photographic documentation.

Incidence

• CNN present at birth or soon thereafter.
• • The melanin pigment in the surface is apparent.
  • Delay in appearance of surface pigmentation may occur from age 1 month to 2 years in the rare "tardive" type.
  • A CNN larger than 9.9 cm in diameter occurs in 1 per 20,000 newborns and larger than 20 cm in diameter in 1 per 500,000 newborns.
• An equal prevalence exists in males and females.
• Autosomal dominant inheritance with incomplete penetrance or multifactorial determination occurs in families with small CNN.
• CNN appear in all races, but, paradoxically, the frequency of small CNN is slightly higher in some populations such as blacks who are at lower risk of developing melanoma than whites.

Embryology

• Melanocytes appear in fetal skin before the 40th gestational day.
• CNN develop in utero after the melanocytes appear but before the sixth antenatal month.
• Supporting evidence for this timing is the documentation of the occurrence of the congenital divided nevomelanocytic nevus of the upper and lower eyelid.
• The eyelid forms the fifth to sixth week in utero and fuses in the eighth to ninth week to reopen during the sixth month.

CLINICAL PRESENTATION

Section 3 of 8  

• Authors and Editors
• Introduction
• Clinical Presentation
• Differential Diagnosis
• Management And Treatment
• Malignant Potential
• Multimedia
• References

History

• The presence of a pigmented lesion is noted at birth or soon thereafter.
• Location and size of a congenital hairy nevus is variable.
• • Small lesions appear more frequently than large lesions.
  • Only 5% of lesions are multiple.
  • Coarse surface hairs develop in more than 50%.

Physical examination

Pathology

• CNN have nevomelanocytes in the epidermis as well-ordered thèques or clusters and in the dermis as sheets, nests, or cords.
• The presence of nevomelanocytes in the lower one third of the reticular dermis is specific for CNN.
• Nevomelanocytes tend to occur in the skin appendages as well.

DIFFERENTIAL DIAGNOSIS

Section 4 of 8  

• Authors and Editors
• Introduction
• Clinical Presentation
• Differential Diagnosis
• Management And Treatment
• Malignant Potential
• Multimedia
• References

Acquired nevomelanocytic nevus: A common mole and is a collection of nevomelanocytes in the epidermis (junctional), dermis (intradermal), or in both areas (compound)

Becker nevus: A large unilateral lesion usually seen on the shoulder of males and consists of a sharply but irregularly demarcated area demonstrating hyperpigmentation and hypertrichosis (Dermatology Online Atlas)

Café-au-lait macules: Flat, light brown surface lesions associated with neurofibromas (Neurofibromatosis)

Congenital blue nevus: A small, well circumscribed, dome-shaped nodule of slate blue or bluish-black color (Dermatology Online Atlas)

Dysplastic melanocytic nevi

• A high incidence of melanoma is observed in these patients.
• Since it is impractical to remove all the pigmented lesions in these patients, those demonstrating recent changes in color and appearance are removed.

Lentigo: Occurs in areas exposed to the sun and possesses a uniform dark-brown color and an irregular outline (Dermatology Online Atlas)

Mongolian spots: Typically occur in the lumbosacral region as a bluish discoloration resembling a bruise (Dermatology Online Atlas)

Nevus sebaceous

• Usually located on the scalp or on the face as a single lesion and is present at birth
• Circumscribed, slightly elevated hairless plaque
• In puberty, becomes verrucous and nodular and may show areas of linear distribution
• View images at Nevus sebaceous

Nevus spilus: A light brown patch or band present since birth that in childhood becomes dotted with small dark brown macules (Nevus spilus)

Pigmented epidermal nevi: A persistent linear, pruritic lesion composed of red, scaling, verrucous papules arranged in one or several lines (Linear epidermal nevus-right leg and Linear epidermal nevus-right leg)

MANAGEMENT AND TREATMENT

Section 5 of 8  

• Authors and Editors
• Introduction
• Clinical Presentation
• Differential Diagnosis
• Management And Treatment
• Malignant Potential
• Multimedia
• References

Management: Two factors influence the treatment of congenital nevomelanocytic nevi, the potential for malignant change and the cosmetic appearance.

• Surgical excision with reconstruction is the mainstay of treatment. Chemical peels, dermabrasion and laser treatments are adjunctive treatment choices. If surgical excision is not feasible, management consists of examination and high-quality photographic documentation for life.

Surgical therapy

• Attempts to remove a large CNN should occur early in life, although it is judicious to wait until age 6 months before operating to decrease anesthetic and surgical risks.
• If direct closure after complete excision is not possible, reconstruction may include serial excision with skin grafts, skin flaps, tissue expansion, autologous cultured human epithelium, or artificial skin replacement.
  • The goals of treatment are to remove all or as much as feasible of the CNN and reconstruct the defect, preserving function and maintaining the aesthetic appearance.
  • Each case requires tailoring of the operation(s) to fit the anatomic defect.
  • The presence of an enlarging nodular mass indicates malignant change and requires immediate treatment. This mass may represent a rare neuroectodermal sarcoma.
  • The incidence of malignant melanoma is higher in the scalp, back, and buttocks and requires removal first.
  • Excision begins in the 6-9 month range, placing procedures 3-6 months apart.
• Special attention was given to giant congenital pigmented nevi of the face by Zuker at the Hospital for Sick Children in Toronto. Complete early excision was recommended because of the cosmetic deformity and because of the life-threatening potential for malignant transformation.
• Evaluation of all small and medium CNN for prophylactic excision should take place before age 12 years. After this age, malignant potential rises sharply.

Adjunctive therapy

• The phenol chemical peel technique is an acceptable alternative method of therapy for those lesions that are too large for excision and primary closure or for lesions in which excision would result in unacceptable scars in areas such as the face. Dermabrasion is useful as an adjunct to increase the depth of the peel and to contour surface irregularities.
• Multiple treatments with the normal-mode ruby laser produced immediate thermal damage to the superficial nests of nevus cells and subsequent remodeling of the superficial connective tissue.
  • When the thickness of the subtle microscopic scar reached 1 mm, it masked the underlying residual nevus cells and achieved a good cosmetic result.
  • Follow-up visits for at least 8 years after laser treatment showed no evidence of malignant change in the treated areas.
• Successful treatment of a giant CNN with high-energy pulsed carbon dioxide laser has been reported.
• Cultured epidermal autografts (CEA) have been used successfully to obtain surface coverage after excision of giant hairy nevi.

MALIGNANT POTENTIAL

Section 6 of 8  

• Authors and Editors
• Introduction
• Clinical Presentation
• Differential Diagnosis
• Management And Treatment
• Malignant Potential
• Multimedia
• References

CNN expands with growth of the child. The risk of melanoma development is proportional to the size of the congenital nevus.

• Lifetime risk of developing a melanoma for patients with a large CNN is 6.3%, but 50% in this group develop melanoma from age 3-5 years.
• Estimated melanoma risk for patients with a large CNN is 8.5% for the first 15 years of life.
• Approximately 40% of the malignant melanomas observed in children occur in large congenital nevi.

When a large congenital nevus involves the head and neck, associated meningeal melanocytosis may be observed, occasionally complicated by seizures, focal neurologic defects, obstructive hydrocephalus, or malignant changes.

In infants, 1% have a small or medium CNN. Malignant potential is less than 1% in this group.

MULTIMEDIA

Section 7 of 8  

• Authors and Editors
• Introduction
• Clinical Presentation
• Differential Diagnosis
• Management And Treatment
• Malignant Potential
• Multimedia
• References

Media file 1:  Congenital nevomelanocytic nevus of the abdomen with a pebbled surface. Courtesy of Patricia K. Gomuwka, MD.
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Media type:  Photo

Media file 2:  Congenital nevomelanocytic nevus of the cheek with coarse surface hairs. Courtesy of Patricia K. Gomuwka, MD.
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Media type:  Photo

Media file 3:  Microscopic examination of specimen from the patient with an abdominal wall congenital nevomelanocytic nevus demonstrates confluence of dermal nevus cell nests and tracking along hair follicles. Courtesy of Carolyn F. Greeley, MD.
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Media type:  Photo

REFERENCES

Section 8 of 8

• Authors and Editors
• Introduction
• Clinical Presentation
• Differential Diagnosis
• Management And Treatment
• Malignant Potential
• Multimedia
• References

• Casson P, Colen S. Dysplastic and congenital nevi. Clin Plast Surg. Jan 1993;20(1):105-11; discussion 111-3. [Medline].
• Egan CL, Oliveria SA, Elenitsas R, et al. Cutaneous melanoma risk and phenotypic changes in large congenital nevi: a follow-up study of 46 patients. J Am Acad Dermatol. Dec 1998;39(6):923-32. [Medline].
• Fitzpatrick TB, Johnson RA, Wolff K. Congenital nevomelanocytic nevus book. In: A Color Atlas and Synopsis of Clinical Dermatology. 3rd ed. 1997:187-190.
• Hopkins JD, Smith AW, Jackson IT. Adjunctive treatment of congenital pigmented nevi with phenol chemical peel. Plast Reconstr Surg. Jan 2000;105(1):1-11. [Medline].
• Imayama S, Ueda S. Long- and short-term histological observations of congenital nevi treated with the normal-mode ruby laser. Arch Dermatol. Oct 1999;135(10):1211-8. [Medline].
• Kay AR, Kenealy J, Mercer NS. Successful treatment of a giant congenital melanocytic naevus with the high energy pulsed CO2 laser. Br J Plast Surg. Jan 1998;51(1):22-4. [Medline].
• Kopf AW, Bart RS, Hennessey P. Congenital nevocytic nevi and malignant melanomas. J Am Acad Dermatol. Aug 1979;1(2):123-30. [Medline].
• Quaba AA, Wallace AF. The incidence of malignant melanoma (0 to 15 years of age) arising in "large" congenital nevocellular nevi. Plast Reconstr Surg. Aug 1986;78(2):174-81. [Medline].
• Rhodes AR. Melanocytic precursors of cutaneous melanoma. Estimated risks and guidelines for management. Med Clin North Am. Jan 1986;70(1):3-37. [Medline].
• Rhodes AR. Benign neoplasias and hyperplasias of melanocytes. In: Fitzpatrick's Dermatology in General Medicine Year. 5th ed. 1999:1026-1032.
• Rhodes AR, Slifman NR, Korf BR. Familial aggregation of small congenital nevomelanocytic nevi. Am J Med Genet. Oct 1985;22(2):315-26. [Medline].
• Sahin S, Levin L, Kopf AW, et al. Risk of melanoma in medium-sized congenital melanocytic nevi: a follow- up study. J Am Acad Dermatol. Sep 1998;39(3):428-33. [Medline].
• Shpall S, Frieden I, Chesney M, Newman T. Risk of malignant transformation of congenital melanocytic nevi in blacks. Pediatr Dermatol. Sep 1994;11(3):204-8. [Medline].
• Siwy BK, Compton CC. Cultured epidermis: Indiana University Medical Center''s experience. J Burn Care Rehabil. Jan-Feb 1992;13(1):130-7. [Medline].
• Weinberg MJ, Al-Qattan M, Zuker RM. Congenital giant pigmented nevi: Clinical features and risk of malignancy. Can J Plast Surg. 1996;4(2):94-98. [Full Text].
• Zuker RM, Iconomou TG, Michelow B. Giant congenital pigmented nevi of the face: Operative management and risk of malignancy. Can J Plast Surg. 1944;3(1):39-44. [Full Text].

Article Last Updated: Mar 10, 2006