1 Dermoscopy Australasian College of Dermatologists G.P Training Module Synonyms Dermoscopy Dermatoscopy Epiluminescence microscopy Skin surface microscopy Incident light microscopy Oil immersion microscopy In vivo cutaneous surface microscopy Definition Non-invasive in vivo technique 10X magnification & bright illumination Transparent medium or Polarised filter …minimise skin surface reflectance Polarised filter Dermoscopy Allows visualisation of subsurface structures and colours not readily observed with naked eye examination Epidermis Superficial dermis Dermo-epidermal junction Robert Johr M.D. “Dermoscopy opens up a world of colour and structure that can’t be seen with the naked eye” Robert Johr M.D. Dx = Benign junctional naevus Uniform pigment network Fades at periphery
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Dermoscopy
Australasian College of DermatologistsG.P Training Module
DefinitionNon-invasive in vivo technique10X magnification & bright illumination
Transparent mediumor
Polarised filter
…minimise skinsurface reflectance
Polarised filter
Dermoscopy
Allows visualisation of subsurfacestructures and colours not readily
observed with naked eye examination
Epidermis
Superficial dermis
Dermo-epidermal junction
Robert Johr M.D.
“Dermoscopy opens up a world of colour and structure that can’t be
seen with the naked eye”
Robert Johr M.D.
Dx = Benign junctional naevus
Uniform pigment networkFades at periphery
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Dx = Superficial spreading melanoma
Atypical pigment networkPseudopodsPeripheral black dotsBlue-grey veil
Brief history of dermoscopy1893 Diaskopie (Unna)1916 Binocular dermatoscope (Zeiss)1958 First portable dermoscope1989 First consensus meeting1991 First atlas (Kreusch)2001 Polarised light dermoscopy
*Almost 500 peer-reviewed publicationson dermoscopy in the last 5 years
Diagnostic algorithms
1987 Pattern Analysis (Pehamberger)1994 ABCD Method (Stolz)1996 Menzies Method1998 7 point checklist (Argenziano)2004 3 point checklist (Soyer)2007 C.A.S.H algorithm (Kopf)
Value of dermoscopy
Diagnostic aid for both:benign and malignant lesionspigmented and non-pigmented lesionsDiagnosis of early melanomaDifferentiation of melanoma from benign pigmented lesions e.g. naevi, seborrhoeic keratoses etcAcral skin & nail apparatus also
Value of dermoscopy
Improves diagnostic accuracy10-27% improvement in Dx of melanomaImproves benign to malignant ratioReduces need for biopsy
*Most valuable in diagnosing benign lesions that may otherwise require biopsy e.g. dark junctional naevi, angiomas, seborrhoeic keratoses
Value of dermoscopy
Improves clinical efficiencyBuilds clinical confidence Bridges clinical exam & pathologySpecialist and primary care setting
*Value is significantly influenced by observer experience
Hand-held monocular instrument Similar to otoscopeL.E.D illuminationPolarised or non-polarised lightContact (wet) or non-contact (dry)Immersion fluid for contact dermoscopyCamera for documentationDigital-ELM (D-ELM) systems for archival
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Colours
Black Stratum corneumDark brown Superficial epidermisLight brown Deep epidermisGrey-blue Papillary dermisSteel blue Reticular dermisRed VasculatureWhite Depigmentation or scarYellow Hyperkeratosis or
sebaceous glands
Polarised light dermoscopyAdvantages
No immersion fluid necessary Non-contact (most DermLites)Quicker
Vascular structuresMilky-red areas
…seen more easilyDx = Nodular BCC
Arborising telangiectasia in sharp focusStructureless pink matrix
Dx = Hypomelanotic invasive SSM
Milky pink/red areasInverse networkAtypical vesselsFaint tan pigmentation
Benvenuto-Andrade C et al Arch Dermatol 2007;143:329-38.
Macro NPCD
PNCDPCD
Dysplastic naevus
Blue-grey veil
NPCD = non polarised contact dermoscopy e.g. Heine Delta-20PCD = polarised contact dermoscopy e.g. DermLite Fluid-IIPNCD = polarised non-contact dermoscopy e.g. DermLite Pro
Dx = Invasive SSM with regression
Blue-grey dots or peppering“Regression structures”
Benvenuto-Andrade C et al Arch Dermatol 2007;143:329-38.
Macro NPCD
PNCDPCD
Congenital naevus
Regressionstructures
Dx = Seborrhoeic keratosis
Milia-like cysts
Benvenuto-Andrade C et al Arch Dermatol 2007;143:329-38.
Macro NPCD
PNCDPCD
Seborrhoeic keratosis
Milial cystsComedo-like openings
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Which instrument?
Welch-Allyn Episcope™
Heine Delta-20®
Non-Polarised dermoscopy
Polarised dermoscopy
DermoGenius
DermLiteHeine Delta 20 + Nikon Coolpix 4500
DermLite Fluid II + Sony Cybershot DSC-W70
Cost
Handheld dermoscopes
$AUD 400.00 - 1900.00
Basic DermLites (polarised) cheapest
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Computerised image analysis
SolarScan (Polartechnics/C.S.I.R.O)MoleMax III (University of Vienna)Fotofinder
Digital dermoscopyMacroscopic imagingData storage and retrievalMonitoringDiagnostic support
SolarScan MoleMax-III
Computerised systems
Still require clinical judgement Still require dermoscopy skillsQuality of imaging not necessarily superior to handheld instruments
Which immersion fluid?
Oil e.g. olive, mineral, Nozoil*messy to apply and stain clothes
Alcohol or aqueous-based e.g. Codan*easier to apply, evaporate quickly
Gel e.g. KY gel, ultrasound gel*don’t run, preferable near eyes or onnail plates
Handling tips
1. Consider dry dermoscopy whenexamining a large number of lesions
2. Move to wet dermoscopy if uncertain3. Ensure good contact between the
glass plate and the skin surface4. Avoid excess pressure (compresses
and obscures vessels)
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Handling tips
5. Position the patient for comfortableexamination
6. The eye must be close to the lens7. Focus the lens where applicable8. Be liberal with immersion fluid
Terminology cont’dDots <0.1mm, brown, black, blue or greyGlobules >0.1 mm, brown, black or redBlotches brown or black, structurelessPeppering fine blue-grey granules of melaninPseudopods peripheral finger-like projections
with bulbous endingsRadial streaming peripherally radiating linesBranched streaks alternate term for radial streaming
and or pseudopodsBlue-grey veil confluent bluish pigmentation with
overlying white ground-glass haze
Blue-grey veilBlue-grey veilBlue-white veil
‘Most significant dermoscopic finding of invasive melanoma’
51% sensitivity97% specificity
synonymous terms
Menzies SW et al. Melanoma Res 1996;6:55-62
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Compact orthokeratosis
Heavily pigmented melanocytes
Terminology cont’d
globules
peppering
dots
blotchesbranched streaks
radial streaming /
pseudopods
blue-grey veil
Terminology cont’dRegression structures scar-like depigmentation with
pepperingStructureless areas regions devoid of structuresCobblestone globules crowded polygonal globulesStarburst pattern symmetrical and radially
streaks Parallel patterns parallel pigmentation within
furrows or ridges on acral skin
Cobblestoneglobules
Regressionstructures
Terminology cont’d
Terminology cont’dStarburstpattern
Mulvehy J, Puig S et al Arch Dermatol 2004
Patterns on acral skinA. Parallel furrow B. Parallel furrow and
Symmetry of structuresCobblestone-globular pattern
Dx = Benign congenital naevus
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Dx = Benign congenital naevus
Cobblestone-globular patternSymmetry of structuresBlue-brown
Dx = Evolving benign compound naevus
Peripheral brown globulesCentral reticular network
Peripheral rim of globules
Sign of evolving naevi80% will show enlargement if followed
Not limited to Spitz naevi
Kittler H et al. Frequency and characteristics of enlargingcommon melanocytic naevi. JAAD 2000;136:316-20
Fibrillar
Furrow
Lattice
Miyazaki JAAD 2005;53:230-6
Acral naevi
Dysplastic naeviMay share clinical features (ABCD criteria) with melanomaRisk marker for melanomaFrequently large i.e. diameter 10mm+Very broad morphologic spectrumCytological and architectural atypia ranges from mild to severe Can be difficult to distinguish from early melanoma
Dysplastic naevi
5 commonest patternsDiffuse reticularPatchy reticularPeripheral reticular + central hypopigmentationPeripheral reticular + central hyperpigmentationPeripheral reticular + central globules
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At the more atypical end of the spectrumRegression structuresBroadened networkAbrupt network cut-offAsymmetric pigment pattern
Blue-grey veil, pseudopods, radial streaming usually absent
Dysplastic naevi
Dx = dysplastic naevus
Disordered networkRegression structuresCentral brown dots
Menzies two criteria for benignitySymmetry of patternSingle colour
3 point checklist allows one of…AsymmetryAtypical pigment networkBlue grey structures
Which lesions to examine?
Assess as many lesions as possibleAssess any changed lesionAssess any lesion causing concernAssess any distinct lesions (ugly duckling)Assess all clinically suspicious lesions
Bowling J et al. Dermoscopy key points. Dermatology 2007;214:3-5.
High risk patient with changed lesionArchitectural, shape or colour changePigmented lesion with extensive
regressionDermoscopically equivocal lesionsAmelanotic/hypomelanotic lesion with
atypical vessels or milky red globulesSpitzoid lesions
Which lesions to excise?
Bowling J et al. Dermoscopy key points. Dermatology 2007;214:3-5.
Which lesions to excise?
Atypical blue naevi Atypical dermatofibromasLesions lacking clinico-dermoscopic
correlationPresence of inverse network
Argenziano G et al. Dermoscopy features of melanoma incognitoJ Am Acad Dermatol 2007;56:508-13.
Special locationsFacelentigo malignamodified by pseudonetworkGlabrous skinacral lentiginous melanoma parallel ridge patternNailssubungal melanomadisruption of parallelism
Face
All pigmented lesions on the face will show a pseudonetwork which is due to follicular openings
A reticular net is not seen because the rete ridges are effaced
Lentigo maligna (in situ melanoma) has a set of unique dermoscopic features
Further ReadingMajor texts/atlasesHandbook of Dermoscopy [Mulvehy]Dermoscopy: The Essentials [Johr]An atlas of surface microscopy of pigmented skin lesions:Dermoscopy [Menzies]An atlas of dermoscopy [Marghoob]