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Congenital Melanocytic Nevi: When to Worry &
When to Treat
Julie V. Schaffer, MD
Associate Professor of Dermatology and PediatricsDirector of Pediatric Dermatology
NYU School of Medicine
Congenital Melanocytic Nevi: When NOT to Worry &
When NOT to Treat
Julie V. Schaffer, MD
Associate Professor of Dermatology and PediatricsDirector of Pediatric Dermatology
NYU School of Medicine
Overview
• evolving definitions and concepts
• natural history
• risks– neurocutaneous melanocytosis– melanoma
• management strategies
Goal: Neither You nor Your Patients Order These Products
McAllister et al Ped Derm 2009
Congenital Melanocytic Nevi: Traditional Concepts
• classic definition: present at birth
• 1-6% of neonates in large series– clinical diagnosis in older studies– dermatoscopic diagnosis more recently– may be more evident in newborns with
darker skin
Congenital Melanocytic Nevi (CMN): Traditional Classification by Size
• small – <1.5 cm final size
• medium – 1.5-20 cm final size
• large– >20 cm final size– ≥9 cm on the head of an infant– ≥6 cm on the body of an infant
Congenital Melanocytic Nevi (CMN): Growth in Proportion to Child
• estimated increase in size from infancy to adulthood– ~2-fold on head– ~3-fold on trunk &
extremities
Congenital Melanocytic Nevi: Histologic Features
• nevomelanocytes extend deeper into dermis and subcutis
• single-file arrangement between collagen bundles
• track along appendages & neurovascular structures
Congenital Melanocytic Nevi:Evolving Concepts
• ‘tardive CMN’, ‘early onset nevi’, ‘congenital nevus-like nevi’– become apparent during infancy or early childhood,
esp. before 2-3 years of age– clinical, dermatoscopic & histologic features identical
to ‘true’ CMN
• 1-4% of children & adults have a CNLN ≥1.5 cm (medium-sized)
• in a recent series, 17% of Italian schoolchildren (ages 12-17y; 592/3406) had a CMN/CNLN ≥0.6 cm
Natural History of Congenital Melanocytic Nevi
• darker or lighter color
• increase in overall thickness
• changes in topography
Development of a Verrucous Surface
Papules, Nodules and ‘Pebbling”
Speckled Lentiginous Nevus: Subtype of CMN
• prevalence of ~2-3%– background tan patch apparent
at birth or during infancy– progressive development of
spots
• patterns reflect origin during embryogenesis– block-like with sharp midline
demarcation– following lines of Blaschko
‘Hybrid’: SLN + Classic CMN
Evolution: SLN → Classic CMN
6 months
12 months
24 months
Speckled Lentiginous Nevus: two variants
• exclusively macular speckles
• papular + macular speckles– ‘garden’ of nevi – any type– ‘SLN syndrome’ – weakness,
dysesthesia, hyperhidrosis
Vidaurri-de la Cruz & Happle. Dermatology 2006Happle. Clin Exp Derm 2009
4 years 10 years 14 years
Haenssle et al. Clin Exp Derm 2009
CMN in Infants: Transient Erosions
• skin breakdown due to skin fragility in neonatal period– evident at birth or during first
few days of life– favors thickest part of nevus
• heal spontaneously over days to weeks
Giam et al Pediatr Derm 1999Gonzalez et al JAAD 2003
CMN in Infants: Proliferative Nodules
• can mimic melanoma, but benign course– rapid growth– atypical histologic features
• clues from comparative genomic hybridization*– no chromosomal aberrations or only numeric changes– most often loss of chromosome 7– not structural changes (gains/losses of chromosomal
fragments) that characterize >95% of melanomas
Bastian et al Am J Pathol 2002Murphy et al JAAD 2008Phadke et al Am J Surg Path 2011*Can use paraffin-embedded tissue
Neurotized Nevi
A
B
C
Type ofNevus Cell
Morphology ofNevus Cell
NeurotizedNevus Neurofibroma
S-100 + +
Leu-7 - +*
GFAP - +*
Myelin basic protein - +*
Factor XIIIa - +
GFAP = glial fibrillary acidic protein *Stains minority of cells
Halo Phenomenon
Regression of Halo CMN
Halo Nevus with Dermatitis
Rolland et al. Ped Derm 2009; Patrizi et al Br J Derm 2005
Tauscher et al. Arch Ped Adol Med 2007
vs Pure ‘Meyerson Phenomenon’: No Regression of the Nevus
1 month 1 year
2 years 3 yearsBonifazi et al. Eur J Ped Dermatol 2001
‘Disappearing’ CMN on the Scalp
• clinical fading over the first 1-4 years of life
• histologic evaluation performed in 2 of 7 children recently reported – nevomelanocytes remained in deep
dermis and adnexae– no inflammation or fibrosis
Strauss & Newton Bishop JAAD 2008Vilarrasa et al JAAD 2008
Strauss & Newton Bishop JAAD 2008
4 months
26 months
birth
21 months
birth
26 months
2 years 4 years
8 mos 6 years
5 mos 4 years
3 years 11 years
‘Peas in a pod’(parallel furrow + crista dotted)
Decreased pigmentation
Minagawa et al. Arch Derm 2011
Desmoplastic Hairless Hypopigmented CMN
• woody induration• progressive loss
of pigmentation• alopecia• intense pruritus
Ruiz-Maldonado et al. Br J Dermatol 2003Martin et al. JAAD 2007
1 month 5 months 2 years
Birth 2 years
Hernandez-Martin et al. Clin Exp Derm 2007
Gass et al. Ped Derm 206
Birth 5 years
S100
Spontaneous ‘Scarification’
Risks of Congenital Melanocytic Nevi
Small- & medium-sized
Large- or giant-sized
Skin disease
Systemic disease
Neurocutaneous Melanocytosis
• proliferation of melanocytes within the leptomeninges (in addition to the skin)– melanocytomas– melanomas
Risk Factors for Neurocutaneous Melanocytosis (NCM)
• multiple satellite nevi– 5-fold increased risk with >20 satellites
(2.5%→12.5%)– ~1/3 of NCM cases without ‘mother ship’
• final size of CMN >40 cm
• ?posterior axial location– inconsistent results– no associated risk in recent large study of
high-risk CMN patients with CNS imaging (n=120)
Kinsler et al. Br J Derm 2008Hale et al. Br J Derm 2005Marghoob AA et al. Arch Derm 2004
Multiple Satellites
associated with >75% of large CMN
in the absence of a ‘mother ship’
Neurocutaneous Melanocytosis• symptomatic NCM
– classically 3–4% of those with high-risk nevi– median onset ~2 y, median survival 6 months– hydrocephalus, seizures, vomiting– with localized mass, median onset ~9 y and more
likely focal sensorimotor deficits
• asymptomatic NCM – + MRI in 5–25% of those with high-risk nevi but no
neurologic symptoms– in 5-y follow-up study, 1 of 10 asymptomatic patients
with +MRI developed neurologic symptoms– ?higher proportion symptomatic, e.g. recent
Montreal series Foster RD et al. Plast Reconstr Surg 2001Hale EK et al. Br J Dermatol 2005Lovett et al. JAAD 2009
Age 5 mos Age 18 mos Age 9 y
Neurocutaneous Melanocytosis: MRI Findings
• best detected by MRI of brain and spine with and without gadolinium– progressive myelination after 6 months of age may
obscure melanin T1 signal
• MRI findings– areas of brain parenchyma (especially temporal
lobes/amygdala) with increased T1 signal – enhancement of diffusely thickened leptomeninges– obvious masses– other CNS/spinal malformations (e.g. Dandy Walker
complex/posterior fossa cysts, intraspinal lipomas)
Neurocutaneous Melanocytosis: Recent Clinical Insights
• study of 120 children with high-risk CMN who underwent MRI of the CNS– mean age at MRI = 2.5 y– mean follow-up = 8 y
• 19% (23/120) had neurologic abnormalities– 11% clinical + MRI (most symptomatic by age 2 y)– 4% MRI only (asymptomatic)– 4% clinical only– included relatively mild clinical findings, e.g.
developmental delay, abnormal muscle tone– significantly more common in boys than girls
Kinsler et al Br J Derm 2008
Risk of Cutaneous Melanoma in CMN –Correlated with Size
>60 cm 4 (2 cutaneous/axial, 2 extracutaneous)
20-60 cm
<20 cm
nevus size N*
204
94
28
multiple 13
melanomas
Kinsler et al Br J Derm 2009
0
0
1 (CNS)
*mean age at entry, 3 y; mean follow-up, 9 y
Risk of Cutaneous Melanoma in CMN –Correlated with Size
>60 cm 4 (2 cutaneous/axial, 2 extracutaneous)
20-60 cm
<20 cm
nevus size N*
204
94
28
multiple 13
melanomas
Kinsler et al Br J Derm 2009
0
0
1 (CNS)
*mean age at entry, 3 y; mean follow-up, 9 y
Risk of Cutaneous Melanoma in CMN –Correlated with Size
>60 cm 4 (2 cutaneous/axial, 2 extracutaneous)
20-60 cm
<20 cm
nevus size N*
204
94
28
multiple 13
melanomas
Kinsler et al Br J Derm 2009
0
0
1 (CNS)
*mean age at entry, 3 y; mean follow-up, 9 y
Caveat with regard to Statistics on Melanoma Risk in CMN
• selection bias in studies can lead to overestimates of melanoma incidence– retrospective case collections– tertiary referral centers– small studies
Krengel et al Br J Dermatol 2006
Melanoma Risk for Small and Medium-Sized CMN
• exact risk not known– estimated to be <1% over a lifetime
• 3 large cohort studies (total n = 680)– mean age at entry ~10 y– mean follow-up period 13.5 y– no melanomas observed
Kinsler et al. Br J Derm 2009Swerdlow et al. JAAD 1995Sahin et al. JAAD 2008
Melanomas in Small and Medium-Sized CMN
• risk virtually all afterpuberty
• tend to arise at the dermo-epidermal junction
Psychosocial/cosmetic concerns
Anxiety level
Ease of monitoring
Natural history
Factors that affect healing/scarring
Type of anesthesia required
THERE IS NOT ONE ‘RIGHT’ ANSWER FOR EVERYONE
Psychosocial/Cosmetic Ramifications
• Face >> other highly visible areas– Larger lesions– Conspicuous sites (eg tip of nose)– ‘Ugly’ lesions (eg thick, warty, hairy)
• Subjectively unappealing lesions, especially in visible sites
• Lesions that are clearly more cosmetically appealing than the resultant SCAR
SOONER
LATER IF AT ALL
Remove before body image begins to
solidify at ~age 4 y
Remove if/when bothersome to the patient
Encourage NOT to remove or to wait
X
There is No ‘Mole Eraser’
McAllister et al Ped Derm 2009
Natural History
• Clinically and/or histologically worrisome changes
• Functional issues (e.g. bulky/exophytic lesions)
SOONER
LATER IF AT ALL
• Signs of involution• Remember that risk of melanoma is low
and begins after puberty
BUTTOCK FOREARM
BLACK OR MOTTLED HOMOGENEOUS TAN
THICK, IRREGULAR, MULTINODULAR THIN, UNIFORM
VERY DENSE MINIMAL
location
pigmentation
topography
hypertrichosis
Factors that Affect Ease of Monitoring
patient/family AWARE, MEDICALLY SOPHISTICATED
RELUCTANT
Anxiety of Child & Family
• High level of anxiety regarding the lesion
• High level of anxiety regarding the procedure
SOONER
LATER IF AT ALL
Factors that Affect Healing/Scarring
• Scalp, lower legs, forearms, palms/soles– Increased tissue flexibility and less scar
spread in 1st year of life
• Risk of functional impairment from scar (e.g. over joint/ circumferential, eyelid margin)
• Sports season currently or in the near future
SOONER
LATER IF AT ALL
Type of Anesthesia Required
• General anesthesia required even if done in an adolescent or adult
• Local anesthesia– Girls: average 9-10 years– Boys: average 10-11 years– VARIES CONSIDERABLY!
SOONER
LATER
Margulis, Alder, Bower Plast Reconst Surg 2009
Small and Medium-Sized CMN: Longitudinal Evaluation
• baseline photography
• (self) skin examination by patient/parents– bring focal changes in color, border or
topography to dermatologist’s attention
Small and Medium:risk ~all after puberty
Large:~half of risk in 1st 5 y
~5-10%
Large/Giant CMN – Risk of Melanoma
• higher risk– posterior axial location– large number of satellite nevi– larger size of CMN (e.g. >50 cm)
• lower risk– restricted to an extremity or the head– satellite nevi themselves
Hale EK et al. Br J Dermatol 2005Bett BJ. J Am Acad Dermatol 2005
Melanomas Associated with Large/Giant CMN
• cutaneous melanomas often arise sub-epidermally, making recognition difficult
• extracutaneous primary sites are relatively common– CNS– retroperitoneum
• occasionally, the primary site is not found
Large/Giant CMN –Prospective Studies on Risk of Melanoma
Ruiz-Maldonado, 1992
Hale, 2005
Egan, 1998
80
46*
170**
8.6 y
7.3 y
5.3 y
2 (2.5%)(cutaneous/axial)
2 (4%)(cutaneous/axial)
4 (2.5%)(all extracutaneous)
* mean age = 8 years**mean age = 6 years
Nstudy follow-up melanomas
Large/Giant CMN – Internet Registry-Based Data on Risk of Melanoma
Nevus Network*(Bett, 2005)
Nevus Outreach* (Ka, 2005)
524 truncal/garment336 head/extremity
379
5.2 y
**
15 (2.9%)1 (0.3%)
(2 extracutaneous)
0
* no physician confirmation** median age = 4 y
N follow-up melanomasstudy
How Does Excision of Large CMN Affect the Risk of Cutaneous Melanoma?
• no clear-cut answer in the literature– trend toward lower incidence of melanoma in patients
whose nevi were excised– however, the largest nevi (which have a higher
melanoma risk) are more likely to be ‘inoperable’
• although early and ‘complete’ excision is often recommended, it is usually impossible to remove every nevus cell in the lesion – location– extensive size– involvement of deeper structures
Other Considerations Regarding Excision of Large CMN
• cons– scar may restrict joint
mobility or impair function
– morbidities of procedures, e.g. discomfort, limitation of activity, risk of infection, anesthesia risk
• pros– functional benefits
(e.g. bulky lesions)– scar more
cosmetically acceptable than nevus
Procedures for Cosmetic and Psychological Benefit (not to decrease melanoma risk)
• neonatal curettage – takes advantage of a cleavage plane between the
upper dermis (where ‘active’ nevus cells are concentrated) and mid dermis in first 2-3 weeks of life
• dermabrasion
• laser resurfacing (e.g. CO2, erbium:YAG)
• other lasers (e.g. Nd-YAG, ruby, alexandrite)
Age 6 mos Age 7 mos, 1 mo after curettage
Age 7 mos, 2 wks after Q-switched ruby laser
Age 8 mos, 1 mo after Q-switchedruby laser
Kishi et al. Br J Derm. 2007
36 mos latertreated at ages:2 wks with CO25 wks with Nd-YAG
Dave et al. Br J Plast Surg 2004
27-y-old woman – melanoma10 y s/p argon laser therapy
Woodrow et al. Br J Derm 2003