Pigmented Lesions
Pigmented lesions are very common in children. Most lesions are benign but can be a sign of a genetic syndrome. Malignant melanoma (MM) in children is commonly associated with giant congenital melanocytic nevi (CMN), so early detection and prevention is crucial. MM comprises 1–3% of pediatric malignancies; 10% of familial atypical multiple mole melanoma (FAMMM) patients develop MM before 20 years of age.
Differential Diagnosis
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Mongolian spots (“dermal melanosis”)
–Present at birth; incidence 90% in black children, 80% in Asian, 65% in Latin-American, 5% in white; disappears in childhood, may persist on distal extremities
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Postinflammatory hyperpigmentation
–Most common pigmentation disorder, follows skin inflammation, resolves within months, more common on dark skin
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Acquired melanocytic nevi (AMN, “moles”)
–Begin in early childhood, darken and increase in size, can become raised during puberty, by late adolescence most people have 20–30; regress and disappear with age
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Dysplastic nevi (“atypical moles”)
–Sporadic or familial (autosomal dominant, FAMMM), incidence 2–5% (adults), usually develop in puberty, risk of malignant change (MM) is 5–10%
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Congenital melanocytic nevi
–1–2% of newborns
–Small CMN: Malignancy risk uncertain
–Giant CMN: 2–15% lifetime malignancy risk, <1/20,000 births, 3% of MM arise in giant CMNs
–LMM: Seen in 30% of giant CMN
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Malignant melanoma (MM) may arise in acquired, dysplastic or congenital nevi, on normal skin or extracutaneous; rarely congenital MM (transplacental); risk factors are fair skin, >50–100 nevi, multiple dysplastic nevi, excessive sun exposure, FAMMM, scleroderma pigmentosum, immunosuppression
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Freckles
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Lentigines
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Tinea versicolor (fungus Malassezia furfur)
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Urticaria pigmentosa: Most common form of mastocytosis; juvenile-onset 7% risk of malignancy and adult-onset 30% risk
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Incontinentia pigmenti: Streaks/whorls
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Café au lait macules: Incidence 10% of children, >5 lesions of >1.5 cm diameter after puberty indicates neurofibromatosis, also in McCune-Albright, tuberous sclerosis, Bloom
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Other nevi: Ito/Ota, Blue, Spitz, Becker, halo, zosteriform, lentiginous, nevus spilus
Workup and Diagnosis
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Mongolian spots: Poorly defined, several cm diameter, blue/grey macules, mostly on buttocks, back, arms, and legs; not on palms, soles, face, mucosal surfaces
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AMN: pink/brown/black macules or papules, <5 mm diameter, 90% flat (junctional), 10% raised, may have hair; sun-exposed skin; not on palms, soles, genitals, mucosal surfaces
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Dysplastic nevi: Pink/brown/black macules or papules, >5 mm diameter, irregular border, on sun-exposed skin
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CMNs: Brown/black/blue, flat/nodular, leathery
–Small CMN: <1 cm, on trunk and proximal limbs
–Giant CMN: >20 cm diameter, may grow hair, midline of back, often satellite nevi
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LMM: May show CNS symptoms (e.g., seizures, hydrocephalus, motor deficits)
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Freckles: Light brown, jagged borders, darken in sun
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Lentigines: Dark brown, any part of skin/mucosa, may be seen with syndromes (Peutz-Jeghers)
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Nevi of Ito/Ota: Shoulder/fronto-periorbital areas
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Urticaria pigmentosa: Darier sign (pruritus/erythema upon stroking), symptoms from mast cell degranulation
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Tinea versicolor: Guttate pattern, can be hypopigmented
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Excisional biopsy: Dysplastic nevi, CMM, MM, and other lesions; distinctive histologic/cytologic features
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MRI of brain and spinal fluid exam: Indicated in giant CMN located on head or paraspinal to rule out LMM
Treatment
- Early detection
–Acquired melanocytic nevi: Regular exams to detect atypical changes
–Dysplastic nevi: Exam every 6–12 months with comparative photographs
–CMN: Small/intermediate need regular exams with careful palpation (MM may arise deep within nevus without surface change)
- Excision
–Malignant melanoma
–Dysplastic and acquired melanocytic nevi: If tender, ulcerating, pruritus, erythema, satellite lesions, regional lymphadenopathy or change in color, size, shape, borders, or texture
–Giant CMN: Early excision if amenable to surgery
–After excision, close follow-up is indicated
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Tinea versicolor: Topical antifungal
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Prevention: Protection from excessive sun exposure
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Book Source Details
- Book Title: In A Page: Pediatric Signs and Symptoms
- Author(s): Jonathan E. Teitelbaum, Kathleen O. Deantonis, Scott Kahan
- Year of Publication: 2007
- Copyright Details: In A Page: Pediatric Signs and Symptoms, Copyright © 2007 Lippincott Williams & Wilkins.
Other Book Chapters Related to Hyperpigmentation
Read excerpts from these other book chapters related to Hyperpigmentation:
Copyright Details: In A Page: Pediatric Signs and Symptoms, Copyright © 2008 Williams & Wilkins.
More About Causes of Hyperpigmentation
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More About This Book:
Title: In A Page: Pediatric Signs and Symptoms
Authors: Jonathan E. Teitelbaum, Kathleen O. Deantonis, Scott Kahan
Publisher: Lippincott Williams & Wilkins
Copyright: 2007
ISBN: 1-4051-0427-9
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» Next page: SKIN PIGMENTATION AND OTHER PIGMENTARY CHANGES (Differential Diagnosis in Primary Care)
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