eMedicine Specialties > Plastic Surgery > Skin

Skin, Congenital Hairy Nevi

Gregory D Pearson, MD, Assistant Professor Clinical, Department of Surgery, Division of Plastic Surgery, Ohio State University
Patricia K Gomuwka, MD, FACS, Consulting Staff, Department of Plastic Surgery, Riverside Regional Medical Center

Updated: Aug 14, 2008

Introduction

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.¹
• Multiple definitions have been used to classify nevi into small, medium, or giant. These include diameter size, total body surface area (TBSA), and ability to excise in one surgical setting.
• Based on diameter, CNN are characterized as small (<1.5 cm), medium (1.5-19.5 cm), and large or giant (>20 cm in adolescents and adults or predicted to reach 20 cm by adulthood).^2,3
• Using the prediction classification, giant nevi have also been described as comprising 9 cm on a child's head and 6 cm on a child's body.⁴

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

• Multiple studies have attempted to elucidate the cumulative risk of developing cutaneous melanoma in patients born with CNN. (Click here to complete a Medscape CME article on lesion diameter as a guideline in cutaneous melanoma.)
• 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.⁵
• A study of the Dutch nationwide pathology database reported a standardized incidence rate of 12.2% of developing melanoma in CNN. This study observed an increase risk of melanoma (in patients with CNN) of 6.4% for men and 14.1% for women when compared to general population rates. Furthermore, patients with giant CNN had an increased risk of 51.6% compared to general population rates.⁶
• For small CNN, risk rates have been reported between 0.8% and 4.9%.
• 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.
• Malignancy should be suspected with focal growth, pain, bleeding, ulceration, significant pigmentary change, or pruritus.

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

• Aesthetic considerations are important.
• Surgical treatment of giant or large CNN is addressed at age 6 months.^4,7
• Procedures used in surgical treatment include serial excision and reconstruction with skin grafting, tissue expansion, local rotation flaps, and free tissue transfer.⁸
• Adjunctive treatment options include chemical peels, dermabrasion, and laser surgeries. For more information, visit Medscape's Aesthetic Medicine Resource Center.
• Surgical excision remains the mainstay of treatment, since other adjunctive treatment options do not fully eradicate the nevus cells.
• Cultured epidermal autographs have been used successfully in select cases.⁹
• Management of small lesions includes close monitoring with photographic documentation versus surgical excision.

Incidence

• CNN are 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; a CNN larger than 20 cm in diameter occurs in 1 per 500,000 newborns.10,11
• An equal prevalence exists in males and females.
• The incidence for small nevi is 1 in 100 births; for medium nevi, 6 in 1000 births; and for large nevi, 1 in 20,000 births.¹²
• 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.¹³

Embryology

• Melanoblasts migrate from the neural crest between weeks 8 and 10 of gestation.¹⁴
• CNN develop in utero after the melanocytes appear but before the sixth antenatal month.¹⁴ 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.¹

Clinical Presentation

History

• The presence of a pigmented lesion is noted at birth or soon thereafter.
• Location and size of a congenital hairy nevus are variable.
  • Small lesions appear more frequently than large lesions.
  • Only 5% of lesions are multiple.
  • Coarse surface hairs develop in more than 50% of lesions and may occur during the first 1-2 years of life.

Physical examination

• Size (in diameter)
  • Small (<1.5 cm)
  • Medium (1.5-20 cm)
  • Large (>20 cm)
• Borders
  • Sharp
  • Regular
  • Irregular
  • Blended with surrounding skin
• Surface
  • Textured
  • With and without hair
• Shape
  • Round
  • Oval
• Color
  • Light brown
  • Dark brown
  • Halo (rare)
• Location – Any site
• Distribution
  • Single lesion
  • Multiple lesions (<5% are multiple)
• Associated findings
  • Neurofibromatosis
  • Leptomeningeal melanocytosis

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. The nevomelanocytes may extend into the subcutaneous tissue.¹⁵
• Nevomelanocytes tend to be associated with skin appendages, vessels, and nerves.¹⁵

Differential Diagnosis

Acquired nevomelanocytic nevus: This is a common mole. It is a collection of nevomelanocytes in the epidermis (junctional), in the dermis (intradermal), or in both areas (compound).¹

Becker nevus: This large unilateral lesion is usually seen on the shoulder of males and consists of a sharply but irregularly demarcated area demonstrating hyperpigmentation and hypertrichosis.¹ Click here for more information and for images.

Café-au-lait macules: These flat, light brown surface lesions are associated with neurofibromas.¹ Click here to view an image of Café-au-lait macules.

Congenital blue nevus: This lesion is a small, well circumscribed, dome-shaped nodule of slate blue or bluish-black color.¹ See eMedicine article Blue Nevi for more information and for images.

Dysplastic melanocytic nevi:¹ A high incidence of melanoma is observed in patients with dysplastic melanocytic nevi. Since removing all the pigmented lesions in these patients is impractical, lesions demonstrating recent changes in color and appearance are removed.

Lentigo: This condition occurs in areas exposed to the sun and possesses a uniform dark-brown color and an irregular outline.¹

Mongolian spots: These lesions typically occur in the lumbosacral region as a bluish discoloration resembling a bruise.¹ Click here to view images of Mongolian spots.

Nevus sebaceous:¹ This lesion is usually located on the scalp or on the face as a single lesion and is present at birth. A nevus sebaceous is a circumscribed, slightly elevated hairless plaque, typically not pigmented like a CNN. In puberty, the lesion becomes verrucous and nodular and may show areas of linear distribution. See eMedicine article Nevus Sebaceous for more information and for images of this lesion.

Nevus spilus: A nevus spilus is a light brown patch or band that is present since birth. In childhood, it becomes dotted with small dark brown macules.¹ Click here to view an image of nevus spilus.

Pigmented epidermal nevi: This condition is characterized by a persistent linear, pruritic lesion composed of red, scaling, verrucous papules arranged in one or several lines.¹ Click here to view an image of pigmented epidermal nevi.

Management and Treatment

Management

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

Surgical therapy

• Attempts to remove a large CNN should occur early in life, although waiting until age 6 months before operating decreases anesthetic and surgical risks.^4,7,14
• If direct closure after complete excision is not possible, reconstruction may include serial excision, excision with skin grafts, skin flaps, tissue expansion with subsequent flap rotation or full thickness skin grafting, autologous cultured human epithelium, artificial skin replacement, and free tissue transfer about tissue expansion.^4,8,14
• 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 appears higher in the scalp, back, and buttocks and requires removal first. This increase in incidence is likely secondary to the total body surface area.
• 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.¹⁶
• Cultured epidermal autografts (CEA) have been used successfully to obtain surface coverage after excision of giant hairy nevi.⁹
• Dermal regenerate templates (Integra) prior to skin grafting have been reported in the literature as a substitute for tissue expansion and rotation flaps.^17,18
• Evaluation of all small and medium CNN for prophylactic excision should take place before the patient is aged 12 years. After this age, malignant potential rises sharply.¹⁹
• Rhodes, Kaplan, and Zaal advocate prophylactic excision of all CNN, whereas Sahin believes small and medium nevi can be monitored clinically.^{6,19,20,21,22}

Adjunctive therapy

• The phenol chemical peel technique has been used to treat nevi that are too large for excision or that are in locations in which excision would lead to undesirable scarring. Multiple peels were required, and the best results were in lightly pigmented, superficial lesions. Surgical excision was still deemed the primary intervention. Dermabrasion is useful as an adjunct to increase the depth of the peel and to contour surface irregularities.23
• Dermabrasion independently has led to a high incidence of hypertrophic scarring (14.6%) without removal of malignancy risk.²⁴
• 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.^25,26,27,28
• 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.
• Results of ruby laser therapy have been varied and malignant risk reduction not determined.
• Successful reduction of pigmentation of giant CNN with high-energy pulsed carbon dioxide laser has been reported. Aesthetic results have ranged from acceptable to hypertrophic scarring (in 50% of patients in one study).^29,30

Malignant Potential

CNN expands with growth of the child. The risk of melanoma development is proportional to the size of the congenital nevus.^6,11,20

• Reports of lifetime risk of developing a melanoma for patients with a large CNN range from 6.3-12.2%. Regarding giant nevi, 50% of the malignancies develop by 3 years of age, 60% by childhood, and 70% by puberty.
• Approximately 40% of the malignant melanomas observed in children occur in large congenital nevi.

When a large congenital nevus involves the head and neck or midline over the trunk, associated meningeal melanocytosis may be observed, occasionally complicated by seizures, focal neurologic defects, obstructive hydrocephalus, or malignant changes. Radiographic imaging, including MRI, is warranted to evaluate melanocytic depositions in the CNS. The baseline MRI should be obtained when the patient is aged 4-6 months. Serial MRIs are frequently required in patients with meningeal melanocytosis.¹⁴

Rates of malignant potential for small and medium CNN are reported between 0.8% and 4.9%.^12,15

Multimedia

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

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

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.

References

1. Rhodes AR. Benign neoplasias and hyperplasias of melanocytes. In: Fitzpatrick's Dermatology in General Medicine Year. 5^th ed. 1999:1026-1032.

2. Nevi and Malignant Melanoma. In: Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 4th. Edinburgh: Mosby; 2004:776-7.

3. Bittencourt FV, Marghoob AA, Kopf AW, et al. Large congenital melanocytic nevi and the risk for development of malignant melanoma and neurocutaneous melanocytosis. Pediatrics. Oct 2000;106(4):736-41. [Medline].

4. Bauer BS, Corcoran J. Treatment of large and giant nevi. Clin Plast Surg. Jan 2005;32(1):11-8, vii. [Medline].

5. 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].

6. Zaal LH, Mooi WJ, Klip H, et al. Risk of malignant transformation of congenital melanocytic nevi: a retrospective nationwide study from The Netherlands. Plast Reconstr Surg. Dec 2005;116(7):1902-9. [Medline].

7. Pearson GD, Goodman M, Sadove AM. Congenital nevus: the Indiana University's approach to treatment. J Craniofac Surg. Sep 2005;16(5):915-20. [Medline].

8. Margulis A, Bauer BS, Fine NA. Large and giant congenital pigmented nevi of the upper extremity: an algorithm to surgical management. Ann Plast Surg. Feb 2004;52(2):158-67. [Medline].

9. Siwy BK, Compton CC. Cultured epidermis: Indiana University Medical Center's experience. J Burn Care Rehabil. Jan-Feb 1992;13(1):130-7. [Medline].

10. Castilla EE, da Graca Dutra M, Orioli-Parreiras IM. Epidemiology of congenital pigmented naevi: I. Incidence rates and relative frequencies. Br J Dermatol. Mar 1981;104(3):307-15. [Medline].

11. 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].

12. Rhodes AR. Melanocytic precursors of cutaneous melanoma. Estimated risks and guidelines for management. Med Clin North Am. Jan 1986;70(1):3-37. [Medline].

13. Shpall S, Frieden I, Chesney M, et al. Risk of malignant transformation of congenital melanocytic nevi in blacks. Pediatr Dermatol. Sep 1994;11(3):204-8. [Medline].

14. Arneja JS, Gosain AK. Giant congenital melanocytic nevi. Plast Reconstr Surg. Aug 2007;120(2):26e-40e. [Medline].

15. Tannous ZS, Mihm MC Jr, Sober AJ, et al. Congenital melanocytic nevi: clinical and histopathologic features, risk of melanoma, and clinical management. J Am Acad Dermatol. Feb 2005;52(2):197-203. [Medline].

16. Zuker RM, Iconomou TG, Michelow B. Giant congenital pigmented nevi of the face: Operative management and risk of malignancy. Can J Plast Surg. 1995;3(1):39-44. [Full Text].

17. Moiemen NS, Staiano JJ, Ojeh NO, et al. Reconstructive surgery with a dermal regeneration template: clinical and histologic study. Plast Reconstr Surg. Jul 2001;108(1):93-103. [Medline].

18. Abai B, Thayer D, Glat PM. The use of a dermal regeneration template (Integra) for acute resurfacing and reconstruction of defects created by excision of giant hairy nevi. Plast Reconstr Surg. Jul 2004;114(1):162-8. [Medline].

19. Rhodes AR, Melski JW. Small congenital nevocellular nevi and the risk of cutaneous melanoma. J Pediatr. Feb 1982;100(2):219-24. [Medline].

20. Zaal LH, Mooi WJ, Sillevis Smitt JH, et al. Classification of congenital melanocytic naevi and malignant transformation: a review of the literature. Br J Plast Surg. Dec 2004;57(8):707-19. [Medline].

21. 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].

22. Kaplan EN. The risk of malignancy in large congenital nevi. Plast Reconstr Surg. Apr 1974;53(4):421-8. [Medline].

23. 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].

24. Rompel R, Moser M, Petres J. Dermabrasion of congenital nevocellular nevi: experience in 215 patients. Dermatology. 1997;194(3):261-7. [Medline].

25. 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].

26. Helsing P, Mork G, Sveen B. Ruby laser treatment of congenital melanocytic naevi--a pessimistic view. Acta Derm Venereol. 2006;86(3):235-7. [Medline].

27. Kono T, Ercocen AR, Kikuchi Y, et al. A giant melanocytic nevus treated with combined use of normal mode ruby laser and Q-switched alexandrite laser. J Dermatol. Jul 2003;30(7):538-42. [Medline].

28. Kono T, Ercoçen AR, Nozaki M. Treatment of congenital melanocytic nevi using the combined (normal-mode plus Q-switched) ruby laser in Asians: clinical response in relation to histological type. Ann Plast Surg. May 2005;54(5):494-501. [Medline].

29. 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].

30. Horner BM, El-Muttardi NS, Mayou BJ. Treatment of congenital melanocytic naevi with CO2 laser. Ann Plast Surg. Sep 2005;55(3):276-80. [Medline].

Keywords

nevus, nevi, congenital nevus, congenital nevi, hairy nevi, hairy nevus, mole, moles, bathing trunk nevus, congenital nevomelanocytic nevus, CNN, garment nevus, giant hairy nevus, giant nevus, giant pigmented nevus, nevus pigmentosus et pilosus, verrucous nevus

Contributor Information and Disclosures

Author

Gregory D Pearson, MD, Assistant Professor Clinical, Department of Surgery, Division of Plastic Surgery, Ohio State University
Disclosure: Nothing to disclose.

Coauthor(s)

Patricia K Gomuwka, MD, FACS, Consulting Staff, Department of Plastic Surgery, Riverside Regional Medical Center
Patricia K Gomuwka, MD, FACS is a member of the following medical societies: American Cleft Palate/Craniofacial Association, American College of Physician Executives, American College of Surgeons, American Medical Association, American Society of Plastic Surgeons, Canadian Society of Plastic Surgeons, Medical Society of Virginia, and Royal College of Physicians and Surgeons of Canada
Disclosure: Nothing to disclose.

Medical Editor

Shahin Javaheri, MD, Chief, Department of Plastic Surgery, Martinez Veterans Affairs Outpatient Clinic; Consulting Staff, Advanced Aesthetic Plastic & Reconstructive Surgery
Shahin Javaheri, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery and American Society of Plastic Surgeons
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Wayne Stadelmann, MD, Stadelmann Plastic Surgery, PC
Wayne Stadelmann, MD is a member of the following medical societies: Alpha Omega Alpha, New Hampshire Medical Society, Northeastern Society of Plastic Surgeons, and Phi Beta Kappa
Disclosure: Nothing to disclose.

CME Editor

Nicolas (Nick) G Slenkovich, MD, Practice Director, Colorado Plastic Surgery Center at Swedish Medical Center
Nicolas (Nick) G Slenkovich, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Medical Association, American Society of Plastic Surgeons, and Colorado Medical Society
Disclosure: Nothing to disclose.

Chief Editor

Jorge I de la Torre, MD, FACS, Professor of Surgery and Physical Medicine and Rehabilitation, Residency Program Director, Division of Plastic Surgery, University of Alabama at Birmingham; Director, Center for Advanced Surgical Aesthetics
Jorge I de la Torre, MD, FACS is a member of the following medical societies: American Association of Plastic Surgeons, American Burn Association, American College of Surgeons, American Medical Association, American Society for Laser Medicine and Surgery, American Society for Reconstructive Microsurgery, American Society of Maxillofacial Surgeons, American Society of Plastic Surgeons, Association for Academic Surgery, and Medical Association of the State of Alabama
Disclosure: Nothing to disclose.

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author Patricia K Gomuwka, MD, FACS to the development and writing of this article.

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