DERMATOSCOPE AND ITS APPLICATION IN DERMATOLOGY

SWATHY

LEKSHMI J L4/12/2014

Non invasive diagnostic

tool which visualizes subtle

clinical patterns of skin

lesions and subsurface skin

structures not normally

visible to the naked eye

HISTORY

1636- Christophorus Kolhaus

1893- Unna

1920- Johann Saphier “Dermatoscopy”

1950- Goldman “Dermoscopy”

PRINCIPLE

Trans illumination and magnification

Visibility of subsurface structures improved by LINKAGE fluids

Immersion oil

Olive oil

Mineral oil

Water

Antiseptic solution

Glycerin

Liquid paraffin

BASIC DESIGN

Achromatic lens -10

Inbuilt illuminating system-

Halogen lamps

Power supply

Inbuilt photography system

TYPES

Instruments without image capturing facility

Image capturing facility

Analytical capability

Videodermatoscope:

Polarised or non polarised video probe that

transmits images to monitor

STEREOMICROSCOPE

Allows an accurate binocular observation with different magnifications (X6-80). The illumination system includes a halogen lamp (12 V/50W)

TECHNIQUE

Non contact/Contact technique

Noncontact avoid risk of nosocomial

infection

Poor resolution & illumination

Contact plates- Graduated/ non

graduated

WHAT IS DERMOSCOPY IS USED FOR?

EVALUATING PIGMENTED SKIN LESIONSEVALUATING NONPIGMENTED SKIN LESIONSENTODERMOSCOPYTRICHOSCOPYONYCHOSCOPY

COLOUR

• Epidermis appears white

• Melanin

• Upper epidermis- Black

• DEJ- Light to dark brown

• Papillary dermis- Slate blue

• Reticular dermis- Steel blue

• White shades- Regression

melanoma, halo nevus, lichenoid keratosis, scars

• Red shades- Increased vascularisation, bleeding

PRIMARY & SECONDARY GUIDE CRITERIA

PRIMARY CRITERIA

• Pigmented network lines and hypo pigmented holes

• Histologically- the length of rete ridges and to

distribution of melanin within keratinocytes of

epidermal rete ridges

• Hypo pigmented holes- supra papillary plates

PIGMENT NETWORK

MELANOCYTIC NAEVUS

• PN slightly pigmented

• Light brown network

• Thin lines and fade gradually at periphery

• Holes are regular and narrow

MELANOMA

• Thickened and

darkened

• Tree like branching at

periphery

• Ends abruptly

• Irregular holes

ATYPICAL NAEVI• Areas of irregular and discrete PN • Asymmetrically distributed

PSEUDOPIGMENT NETWORK

• Homogenous pigmentation interrupted by

hypopigmented hair follicles and sweat gland openings

• Uniform & symmetric in colour and pattern – Benign

• Nonuniform & asymmetric – Lentigo maligna

RADIAL STREAMING AND PSEUDOPODS

• Histologically- confluent junctional nests of atypical

melanocytes

• Linear extension of pigment at the periphery of

lesion

• Curved finger like projections, dark brown or black

MELANOMA

PIGMENTED GLOBULES

• Round or oval, dark brown or black >1 mm

• Histologically -nests of pigmented melanocytes at

the junction in papillary dermis

• Milky red globules- nests of melanoma cells with

increased vascularity

Cobble stone pattern- Benign melanocytic lesion

Dark or slate blue irregularly distributed- MM

SECONDARY CRITERIA

PIGMENTED DOTS

• Small round or irregularly shaped structures• Black or dark brown• Focal accumulations of free melanin or no. of highly

pigmented melanocytes in cornified layers of epidermis

BENIGN MELANOCYTIC LESIONS

• Homogenous in colour

• Regular in shape, size and distribution

MELANOMA OR ATYPICAL LESION

• Dots occur at periphery

• Irregular in size, shape and distribution

BLUE- WHITE VEIL

• Ground glass area of pigmentation

• Blue grey to white in colour

• Compact orthokeratosis and hypergranulosis

• Confluent nests of heavily pigmented melanocytes in dermis

• Melanoma and Spitz nevi

SPITZ NAEVUS – WHITISH BLUE VEIL

BLUE GREY AREAS

• Colouration varying from grey-blue to deep grey

• Melanin/ hemosiderin within melanocytes and melanophages

• Melanoma regression

STEEL BLUE AREAS

Structure less, grey-blue and homogenously diffuseBlue nevi

DEPIGMENTATION

Fibroplasia, telangiectasias and loss of melanin

INVASIVE MELANOMA

NEGATIVE PIGMENT NETWORK

• Lighter serpiginous lines making up cords and darker areas resembling elongated tubular or curved globular like structures

• Thin elongated hypo pigmented rete ridges accompanied by the presence of large nests of heavily pigmented melanocytic cells at dermal papillae

• Highly specific for melanoma

CHRYSALIS STRUCTURES

• Thick, short, bright, whitish linear structures

• Orthogonally oriented• Changes in composition

and orientation of collagen• Melanoma, Spitz nevi,

Dermatofibroma ,BCC

NONSPECIFIC GUIDE CRITERIA

MILIA LIKE CYSTS

• Keratin filled cysts• White-yellow

circular, 0.1- 1 mm

COMEDO LIKE OPENINGS

• Keratin filled within invaginations of epidermis

RED- BLACK LAGOONS

• Small, well defined, round or oval areas

• Thrombi within the vascular spaces of papillary dermis

• Hemangioma and angiokeratoma

MAPLE LEAF- LIKE PIGMENTATION

Heavily pigmented basaloid cellsBCC

VASCULAR PATTERNS

Kreusch& Koch Thick arborizing vessels- Pigmented BCC Corona vessels- Sebaceous hyperplasia Comma shaped- Dermal nevi

Point vessels- Melanocytic trs, Superficial epithelial trs Hairpin vessels- angiogenesis Linear irregular vessels- Malignant melanoma

PIGMENTED SKIN LESIONS

• MELANOCYTIC LESIONS• Melanoma• Benign naevi• Atypical naevus

• PIGMENTED BCC• SEBORRHOEIC KERATOSIS• VASCULAR LESIONS• MISCELLANEOUS

• Dermatofibroma • scc insitu

Benign MelanocyticVs

Malignant melanoma

Pattern analysisABCD rule

Menzies’ method7 point checklist

PATTERN ANALYSIS

Step 1: Melanocytic or Non melanocytic

Step 2: Identify the melanocytic lesion by CASH

MELANOCYTIC NAEVI

• Few colours, regular design, symmetrical pattern

MALIGNANT MELANOMA• Several colours, architectural disorder, asymmetry

heterogeneity

ABCD RULEAsymmetryBorderColourDifferent structural components

MENZIES METHOD

7 POINT CHECKLIST

MOLE MAPPING

• To monitor atypical melanocytic lesions over time

• 3-6 monthly intervals in multiple atypical lesions

NON MELANOCYTIC LESIONS

PIGMENTED BCC

• Pink colour• Absence of pigment

network• Arborizing vessels

PIGMENTED BCC

Negative feature: Absence of pigment network + At least one Linear and arborizing telangiectasisLeaf-like or structure less areas on the periphery Multiple blue gray nodule Large blue gray ovoid nestsFocal ulcerationSpoke wheel areas

SEBORRHEIC KERATOSIS

• Multiple milia like cysts• Comedo-like openings• Hyperkeratosis/ fissures/

ridges• Light brown finger like

structures• Hairpin blood vessels• Cerebriform apperance

SK with HK, Fissures, Ridges

SK- Cerebriform apperance

ACTINIC KERATOSIS

• Pink/ red pseudo network& erythema surrounding the hair follicle

• White to yellow surface scales• Linear or wavy vessels surrounding the hair follicle• Hair follicle openings filled with yellowish keratotic

plugs

SEBACEOUS HYPERPLASIA

• Central follicular opening &surrounding yellow nodule

• Vessels may extend to the centre of lesion

• Never arborizing

DERMATOFIBROMA

• Central white scar like patch

• Peripheral delicate network

• Absence of melanocytic features

CLEAR CELL ACANTHOMA

• Homogenous, symmetrically or bunch like arranged pinpoint like capillaries

VASCULAR LESIONS

PYOGENIC GRANULOMA

• Reddish homogenous areas

• White collarette• Ulceration• White rail lines

intersecting the lesion

HEMANGIOMA

Red homogenous area

KAPOSI’S SARCOMA

• Bluish-reddish colouration

• Rainbow pattern- most distinctive feature

• Scaly surface and small brown globules

ENTOMODERMOSCOPY

LUPUS VULGARIS

• Orange- yellowish globules or areas• Enhances the diagnosis

LEISHMANIASIS

Orange- yellowish globules or areas, linear vessels, erythema, follicular plugging, hyperkeratosis, central ulceration

SCABIES

• Jet with contrail apperance

PEDICULOSIS

• Ovoid brownish structures

• Ovoid translucent empty structures- empty nits

COMMON WART

• Multiple densely packed papillae with a central dot or loop, surrounded by whitish halo

• Small red to black dots

PLANTAR WART

• Prominent haemorrhage within yellowish papilliform surface

PLANE WART

Regularly distributed red dots, light brown to yellow background

GENITAL WART

Mosaic pattern, finger like or knob like pattern, nonspecific pattern

MOLLUSCUM CONTAGIOSUM

• Central pore or umbilication

• White to yellow amorphous structures

• Peripheral linear or branching vessels (red corona)

TICK BITES

• Legs protruding from the skin surface

RARE SKIN INFECTIONS

TUNGIASIS Nodule with a central targetoid brownish ring, which in turn surrounds a central, black, pore.

CUTANEOUS LARVA MIGRANS Translucent brownish structure less areas in a segmental arrangement, corresponding to the body of the larva

MYCOSES

TINEA NIGRAReticulated pattern , consisting of superficial fine, wispy, light-brown strands or 'pigmented spicules’

ONYCHOMYCISIS White to yellow streaks and homogeneous areas in the distal nail plate.

TRICHOSCOPY

FINDINGS

• Vascular patterns• Follicular& perifollicular signs• Hair shaft characteristics

NORMAL SCALP

• Red loops

• Perifollicular pigment network

• Follicular unit- 2-4 terminal hair

1-2 vellus hair

SCALP PSORIASIS

Twisted red loops

SEBORRHOEIC DERMATITIS

Arborizing red lines

ALOPECIA AREATA

• Yellow dots• Short vellus hairs• Black hairs• Tapering and

broken hairs

TRICHOTILLOMANIA

• Hairs broken at different levels• Longitudinal splitting of hair shaft

ANDROGENETIC ALOPECIA

• Variability in hair shaft diameter >20%

• Peripilar signs• Yellow dots

PRIMARY CICATRICIAL ALOPECIA• Follicular ostia -• Fibrous tract+

TELOGEN EFLUVIUM

• Yellow dots and short vellus hairs

• Upright regrowing hairs

TINEA CAPITIS• Comma hairs• Corkscrew hairs• Zigzag hairs and interrupted (Morse code-

like) hairs

HAIR SHAT DISORDERS

MONILETHRIX : beading (nodes)

CONGENITAL

T. invaginata : bamboo, matchstick

CONGENITAL

Pili torti : flattened with irregular twists

CONGENITAL

Wooly hair : crawling snake,short wave

CONGENITAL

T.Nodosa : white nodes,brush-like ends

Acquired

Trichomycosis : yellow concretions

Acquired

ONYCHOSCOPY

• Examine the nail plate from above as well as end-on

• Pigment in the top of the nail plate - proximal matrix

• Pigment at the bottom of the nail plate - distal matrix or

nail bed.

Melanocytic naevus of the nail apparatus is characterised by:

Regular parallel lines Brown background Granular inclusions

EPITHELIAL MELANIN

• Homogeneous longitudinal thin grey lines

• Light brown to dark grey background colour.

NAIL MATRIX MELANOMA

• Longitudinal brown to black parallel lines with irregular

colouration, spacing, or thickness

• Disruption of parallelism

• Brown background

• Hutchinson sign: pigmentation of cuticle

• Nail plate fissuring or destruction

MicroscopicHutchinson’ssign

Blood spots are well-circumscribed dots, globules or blotchesRed, purple, blue, brown or black

SUBUNGUAL HAEMORRHAGE

NAILFOLD CAPILLOROSCOPIC INSTRUMENT

SD PATTERN

Irregular extravasationsDilated loopsBudding

Benefits

• Dermoscopy increases the sensitivity for the

diagnosis of melanoma without decreasing the

specificity

• Dermoscopy reduces the number of unnecessary

biopsies.

• Dermoscopy allows digital surveillance and

monitoring of in patients with multiple atypical

nevi.

• Dermoscopy is useful in the diagnosis and

differentiation of nonmelanocytic benign and

malignant tumors

Limitations

• The diagnostic accuracy of dermoscopy- experience in the interpretation of dermoscopy .

• May fail to recognize melanomas that lack specific dermoscopic criteria (featureless melanomas) .

• Dermoscopy alone cannot establish the diagnosis of malignancy; histopathologic examination remains the gold standard.

THANK YOU