New classification of nevi based on Dermoscopy
cobblestone pattern globular p reticular p homogenous blue p starburst p not specific p
New classification - pigment distribution
Uniformly pigmented Central hyper pigmented central hypo pigmented eccentric hyper pigmented eccentric hypopigmented multifocal hyper/ hypo pigmented
New classification - color
Light brown Dark brown Red White Blue Black Grey
2 main categories of melanocytic nevi
Congenital
Acquired
Categories of congenital nevi
Large
Medium
Small
Categories of acquired nevi
Junctional, compound, dermal
Spitz
Blue
Other
Incidence of congenital nevi
Likely 1% or lower
Risk of melanoma in CN?
Small - medium 0-5% lifetime risk
Giant 5-15%
Origin of melanoma in CN
Dermis
Congenital nevis, dermoscopic features
- Asymmetry
- Pattern
a. Multicomponent
b. Globular (cobblestone)
c. reticular
d. Homogenous - Pigmentation
a. Uniform
b. Hypo/ hyper-pigmented
Congenital nevis, additional dermoscopic features
Hypertrichosis
Perifollicular hyper/ hypo-pigmentation
Vessels
Definition giant congenital nevus
> 20 cm adult
6 cm birth
9 cm birth, head
Management giant congenital nevus
- MRI to r/o neurocutaneous melanosis
- Early surgery if appropriate
- Follow up examination every 6 months.
Management small/ medium congenital nevi
If suspicious features excise If change in lesion excise if difficulty with documentation excise If unable to do full excision do partial excision of suspicious area. If unable to excise follow up.
What is histopathological correlate of globular pattern?
Nests of melanocytes at the Dermoscopy-epidermal junction and dermis
What is dermoscopic hallmark of nevi in childhood?
Globular pattern
What types of nevi contain globular pattern?
Small congenital
compound
dermal
Arguments for common histiogenetic background globular nevi
- Histopath features of small CMN, compound nevi, dermal nevi often indistinguishable.
- All 3 types characterized by same morphologic pattern
- Histopathologic studies report on high number compound or dermal nevi in early childhood and late adulthood.
New classification globular nevi
- Previously characterized as small congenital nevi, compound nevi +/- dysplasia, dermal nevi.
- Development dt endogenous pathway
- Life-long persistence
What is hallmark of Nevis in adults with development at puberty
Reticular pattern
Reticular pattern, histopath correlation
proliferation of malanocytes along elongated retentions ridges
In what type of nevi is reticular pattern typically seen?
Junctional nevi +/- dysplasia
Association between nevus and skin type
ST I. Light brown, central hypo-pigmentation
ST II. Light brown, multi-focal hyper/ hypo-pigmentation
ST III. Light brown, multi-focal hyper/ hypo-pigmentation
ST IV. Dark brown, central hyper-pigmentation.
Reticular nevi pathway
“True” AMN
Development in early adolescence, exogenous pathway (UV induced), disappearance later in life dt involution and or regression.
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Module 1: Algorithms and the Elephant Approach9
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Module 2: Chaos and Clues35
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Module 3: Benign non melanocytic lesions16
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Module 4: Keratinocyte carcinoma14
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Module 5: Melanocytic Nevi32
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Module 6: Facial lesions39
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Module 7: Acral lesions21
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Module 8: Melanoma67
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Pink tumours48
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Mucosal lesions31
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Difficult benign lesions62
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Nail lesions74
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Rare skin tumours77
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Rare skin tumours COPY65
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Revised pattern analysis65
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Recent Advanced In Dermoscopy, Articicle20
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Screening Children29
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Skin Cancer Prevention BCCA23
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Screening Children Part 2 - Spitzoid Nevi23
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Screening Children Part 3 Melanoma6
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Screening young adults17
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Screening older patients15
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Patients with multiple nevi13
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Dermoscopy and treatment decision for non melanoma skin cancer0
