TUTORIAL PRESENTATION

DERMOSCOPY :PIGMENT v/s VASCULAR

BY Dr. D R DHAKED

INTRODUCTION• Also k/a dermatoscopy, epiluminescence microscopy

[ELM], incident light microscopy, skin surface microscopy

• Non invasive diagnostic technique for in vivo observation of pigmented skin lesions,

• Provides a horizontal view of the lesion, • Permits recognition of morphologic structures not

visible by naked eye• Magnification ranges from 6x to 40x. • Widely used dermatoscope has a 10-fold

magnification

Technical Procedures and Equipment• Lesions are inspected using a hand-held dermatoscope, a

stereomicroscope, a camera, or a digital imaging system• Lens is paired with a bright halogen beam • Immersion fluid (mineral oil, alcohol or water) placed on

lesion eliminates surface reflection and renders cornified layer translucent,

• Allows better visualization of pigmented structures within epidermis, dermoepidermal junction and superficial dermis.

• Size and shape of vessels of superficial vascular plexus can be easily appreciated

• Examination of vessels is of particular interest in diagnosis of nonpigmented lesions,

• In diagnosing melanoma, dermoscopy has been reported to allow 10-27% higher sensitivity than clinical diagnosis by the naked eye [Mayer 1997].

Videodermatoscope

Stereomicroscope

Dermaphot Dermatoscope

Understanding of different dermoscopic features is important to formulate a diagnosis

Pattern analysis i) Pattern recognition:- Skin lesion can be placed in to one of nine groups• Reticular pattern -

– Defined by a pigment network. – Typical pigment networks are seen in acquired melanocytic naevi and some lentigo. – A fine peripheral network is seen in dermatofibroma. – An atypical pigment network has a high specificity for melanoma

• Globular pattern - – Presence of numerous, variously sized, round to oval structures with various shades of

brown and gray-black coloration. – Indicative of junctional proliferation of melanocytes – Seen in acquired melanocytic naevi in young people

• Homogenous pattern - – A diffuse area of colour in the absence of a pigment network or other distinctive local

features. – May seen in melanocytic lesions or blue naevi and seborrhoeic keratoses

• Multicomponent - – Combination of features such as globular reticular or reticular homogenous, – Combination of three or more patterns within a lesion (multicomponent) can be

suggestive of melanoma

• Cobblestone - – Closely aggregated, large somewhat angulated globules resembling a cobblestone. – Result from large dermal nests of melanoctyes found in dermal naevi

• Parallel pattern –– Indicative of acral lesions.– A parallel-like fingerprint pattern can be seen in solar lentigo

• Starburst pattern - – Pigmented streaks in a radial arrangement at edge of a pigmented skin lesion. – Indicative of spitzoid lesions including pigmented spindle cell naevus of Reed, and

spitzoid melanoma• Lacuna -

– Several to numerous, smooth-bordered, round to oval, variously sized structures. – Morphologic hallmark is their striking reddish, blue-purplish or black coloration. – Indicative of angioma

• Unspecific - – Relatively featureless lesions that cannot be categorised by any of the above. – This pattern can represent a subtle melanoma

Dermatofibroma with reticular pattern in anular distribution

Atypical reticular pattern in a melanoma in situ

Typical reticular pattern in a Clark nevus

Typical globular pattern in a Clark nevus, compound type

Typical cobblestone pattern in a papillomatous dermal nevus (Unna nevus)

Brownish-gray homogeneous pattern in a blue nevus

Brownish-gray homogeneous pattern in a dermal nevus

Typical homogeneous pattern in a blue nevus

Lacunar pattern in an angiokeratoma

Lacunar pattern in an angioma

Typical starburst pattern in a Reed nevus

Parallel-furrow pattern, in an acral nevus lattice-like pattern, in an acral nevus

Multicomponent pattern in a congenital speckled nevus (nevus spilus)

Multicomponent pattern in a malignant melanoma

ii) Pattern comparison• Patients with multiple acquired melanocytic naevi will

often have lesions showing a similar dermoscopic pattern

• Any lesion found to have a different dermoscopic pattern, should be treated with suspicion.

• Patients age should be taken into consideration as the dermoscopic morphology of acquired melanocytic naevi change as patients get older

• Globular in teenage years• Reticular in 30-40 year olds• Homogenous in the over 50’s

Colour

• Pigmentation of lesion is evaluated in terms of colour(s): black, dark brown, tan, grey, steel blue, purple, white, yellow and red.

• Understanding colour is important as it helps determine the level of melanin in the skin:– Black - superficial epidermis– Brown - epidermis– Grey - papillary dermis– Blue - reticular dermis

• Greater the number of colours more likely the lesion is to be malignant.

• But not true in case amelanotic / hypomelanotic melanoma

 Black: epidermal melanin

 Black: thrombus

 Dark brown: junctional melanin

 Tan: junctional melanin

 Grey: upper dermal melanophages

 Blue: deep dermal melanin

 Purple: vascularity or bleeding

 Red: vascularity or bleeding

 White: regression or scarring

 White: keratin

 Yellow: keratin

 Multiple colours : melanoma

Symmetry• Clinically, evaluated in terms of shape. • Symmetry of shape suggests a benign lesion, • Asymmetry suggests melanoma • By dermoscopy, symmetry is evaluated in terms of pigment

pattern (colour and/or structure). • Symmetrical pigment pattern is typical of benign skin lesions. • Complete asymmetry, lesion may be malignant or atypical naevi.• Uniform pigment also called ‘homogeneous’ (benign), • Irregular pattern called ‘heterogenous’ (atypical or malignant). • The degree of symmetry / asymmetry is quite subjective, • It must be considered in combination with all other dermoscopic

and non-dermoscopic features to help formulate a diagnosis

 Homogeneous, symmetrical lesion

 Symmetrical shape & structure

   Homogeneous structure with asymmetrical shape

 Asymmetrical shape & pattern (atypical naevus)

   Symmetrical shape, 

asymmetrical pattern (melanoma)

Lesion specific features (local features)• Melanocytic lesions are made up of three types

of structure:– Pigment network – Amorphous structureless areas (blotches) – Dots and globules

• Benign lesions tend to have only one or two of these structural patterns in a symmetrical distribution.

• Malignant lesions tend to have areas of network, amorphous structures and scattered globules in an atypical distribution

Pigment network

• Formed by melanocytes or melanin in basal keratinocytes. • Dense pigment rings (the grid) are due to projections of

rete pegs or ridges. • Paler ‘holes’ are due to projections of dermal papillae.• A typical pigment network is characterised by a light to

dark-brown pigmented, regularly meshed and narrowly spaced network

• Distributed more or less regularly throughout lesion • Usually thinning out at the periphery. • Seen in some typical and atypical benign melanocytic

lesions.

Typical or Regular pigment network

 Ink-spot lentigo

 Lentigo simplex

 Solar lentigo

 Solar lentigo

 Junctional naevus

 Junctional naevus

 Compound naevus

 Atypical naevus

 Junctional naevus Starburst pattern

 Compound naevus Interrupted network

 Atypical naevus Annular network

 Atypical naevus 

Spoke-wheel network

Atypical or irregular pigment network• Characterised by a black, brown, or grey, irregularly meshed

network, • Distributed more or less irregularly throughout the lesion • Usually ending abruptly at the periphery. • Streaks, brownish-black linear structures of variable thickness, not

clearly combined with pigment network lines, • Branched streaks are seen in dysplastic naevi and some

melanomas.• Radial streaming or parallel linear extensions at edge of lesion

often represent radial growth phase of melanoma.• Pseudopods are bulbous projections at edge of lesion due to

junctional nests of abnormal melanocytes in invasive melanoma• Thick lines (broadened network) are characteristic of melanoma,

and are accompanied by irregular holes.

Irregular pigment network: red arrows point to branched streaks, black arrows to broadened network, asterisk to streaming, thin arrow to pseudopods

 Dysplastic naevus

 Dysplastic naevus

 Recurrence after excision

 Atypical lentiginous hyperplasia

 Melanoma

 Melanoma

 Melanoma

 Melanoma

Pseudonetwork: facial skin• Term ‘pseudonetwork’ is used when annular

pigmentation is seen around hair follicles on facial skin. • On face, it may be difficult to differentiate benign

naevi, lentigo, solar keratoses, lichenoid keratosis and early lentigo maligna.

 Solar lentigo

 Solar lentigo

 Solar keratosis

 Lichenoid keratosis

Negative network• White reticular pattern due to elongated rete pegs. • Characteristic of melanoma but also sometimes seen in

Spitz naevi and some dysplastic naevi. • It may resemble the pattern seen in scars on lower leg

(atrophie blanche). • It should not be confused with pale colour separating

globules of a benign naevus.

 Melanoma

 Melanoma Green arrows point to negative network

 Atrophie blanche

 Benign naevus

Dermoscopy of palmo-plantar melanocytic lesions

• ‘Parallel pattern’ refers to network seen within most melanocytic naevi on palmar and plantar surfaces.

• Parallel furrow pattern: pigmented furrows• Lattice pattern: pigmented furrows and lines crossing these• Fibrillar/filamentous pattern: delicate pigmentation crossing

the skin markings• Parallel ridge pattern: pigmented ridges (white dots represent

sweat duct openings), highly specific for melanoma in volar sites.

• There is no obvious parallel pattern in homogenous-type naevi on volar sites.

 Parallel furrow pattern

 Lattice pattern

 Lattice pattern

 Fibrillar pattern

 Fibrillar pattern

 Fibrillar pattern Dysplastic naevus

 Mixed pattern

 Parallel ridge pattern Melanoma

Dermoscopy of palmo-plantar melanocytic lesions

Amorphous areas (blotches) • Diffuse pigmentation without specific structural features• Brown blotches may be due to pigment in basal layer or

papillary dermis and arise when rete ridges are flattened out.• Homogeneous blue pigmentation is seen in blue naevus.• Diffuse amorphous areas

– Solar lentigo, Benign naevus, Blue naevus• Irregular blotches are sometimes only dermoscopic feature of

melanoma. Blue-white veil - • An irregular, confluent, grey-blue to white-blue diffuse

pigmentation • Caused by an acanthotic epidermis with focal hypergranulosis

above sheets of heavily pigmented melanocytes in upper dermis• Has high specificity for melanoma

 Solar lentigo

 Benign naevus

 Benign naevus

 Blue naevus

 Dysplastic naevus

 Melanoma

 Melanoma

 Melanoma Also has irregular network

Irregular amorphous areas

Diffuse amorphous areas

Dots and globules• Sharply circumscribed, usually round or oval, variously sized

brown, black or blue-grey structures. • Colour determines their site:

– black dots are due to free melanin in the stratum corneum, – brown globules are due to junctional nests of melanocytes, – blue or grey dots are due to melanophages in dermis.

• Benign lesions tend to have central black dots and globules.• Dots associated with a pigment network may be due to pigment

on ridges (superimposed on network grid) or papillae (in the holes).

• Circumferential brown globules are seen in enlarging dysplastic naevi.

• Diffuse blue/grey dots in absence of a pigment network are characteristic of lichenoid keratosis.

• Clusters of tiny brown dots are characteristic of melanoma.

 Central dots

 Central globules

 Uniform globules Dermal naevus

 Cobblestone pattern Compound naevus

 Scattered dots

 Peripheral globules Atypical naevus

 Eccentric globules Dysplastic naevus

 Diffuse blue/grey

dots Lichenoid keratosis

Dots and globules in benign lesions

 Black dots

 Brown dots

 Grey dots

 Peripheral dots

Dots and globules in melanoma: yellow arrows

Dots may be seen in pigmented basal cell carcinoma and rarely in seborrhoeic keratoses.

Dots in basal cell carcinoma: yellow arrows

Dermoscopic structures of non-melanocytic lesions

• Some specific dermoscopic structures are helpful in diagnosis of non-melanocytic lesions.

• These include:– Leaf-like areas– Blue ovoid masses– Milia-like cysts– Fissures and comedo-like openings

Leaf-like areas• Leaf-like areas are grey, brown or blue shiny, discrete bulbous

structures unassociated with a pigment network (structureless).

• They are seen on edges of pigmented basal cell carcinoma, • Some may not appear very like a leaf, in which case they are

better known as ‘structureless areas’. • Moth-eaten edges of solar lentigos also sometimes appear

leaf-like.

 Leaf-like areas: BCC

 Leaf-like areas: BCC

 Structureless areas: BCC

 Leaf-like areas: 

solar lentigo

Blue ovoid masses• Are large discrete pigmented round, oval or bullet-shaped blue

structures • Characteristic of basal cell carcinoma. • When the structure has radial projections, they are called ‘spoke-

wheel areas’. • They are often found within leaf-like or structureless areas. • Blue blotches that are sometimes seen in melanoma are

irregular, less well defined and appear out of focus.

   Blue ovoid masses: BCC

 Spoke-wheel areas: BCC

 Blue blotches: 

melanoma

Milia-like cysts• Round white or yellow lesions due to intraepidermal

keratin. • Characteristically found within a seborrhoeic keratosis. • May arise within dermal melanocytic naevi, BCC and

melanoma.

 Seborrhoeic keratosis

 Seborrhoeic keratosis

 Compound naevus

 Pigmented BCC

Fissures and comedo-like openings• Brown-yellowish or brown-black, roundish to oval or even irregularly shaped,

sharply circumscribed structures• Comedo-like openings are sometimes called ‘crypts’. • Little craters and tend to be dark brown, like irregular globules. • Often associated with fissures (clefts).• Characteristic of seborrhoeic keratoses, • May be found in dermal naevi. • Rarely, in melanoma

 Comedo-like openings: seborrhoeic keratosis

 Fissures: seborrhoeic keratosis

 Cysts & crypts: seborrhoeic keratosis

 Comedo-like openings: 

compound naevus

Cerebriform structure• Seborrhoeic keratosis may have a cerebriform or brain-like pattern. • Pattern is composed of fissures and ridges mimicking the gyri and

sulci of the brain.• Useful sign in the absence of comedo-like openings or milia-like

cysts.

 Fissures/comedo-like openings Enhanced by tanning cream

Fingerprint-like structures• Descriptive term for tan or dark-brown, fine parallel cord-like

structures • Characteristically seen in seborrhoeic keratoses and solar

lentigo. • Wider cords are called ‘fat fingers’. • Fat fingers are also rarely seen in melanoma.

 Fingerprint-like structures

 Fingerprint-like structures Crypts in elevated centre of lesion

 Fat fingers

 Fat fingers

The border of skin lesions

• Clinical characteristic of an irregular edge is often seen in melanoma, but is quite common in benign lesions too

• Border can fade out (often seen in atypical naevi) or be sharply demarcated in a small segment (typical of melanoma).

• Sharp cut-off may also occur all the way around in a regular or irregular pattern.

• ‘Moth-eaten’ edge, seen as concave areas at edge of a lesion. • Seen in ephilis and some flat seborrhoeic keratoses and lentigos

 Fading border benign naevus

 Localised sharp cut-off: melanoma

 Sharp cut-off all round: melanoma

 Moth-eaten edge: 

ephilis

Crystalline structures• Shiny, bright white, parallel or orthoganol or disordered

linear streaks or short lines. • Seen by contact or non-contact polarised dermoscopy. • Are due to excessive collagen • May be seen in dermatofibroma, scar, basal cell carcinoma

with fibroplasia, squamous cell carcinoma, Spitz naevi and melanoma.

 Dermatofibroma

 Pigmented basal cell carcinoma

 Superficial basal cell carcinoma

 Melanoma

Vascular structures and pattern

• Vascular structures show up better in hypopigmented or nonpigmented lesions, or in lighter areas of pigmented tumors.

• Most important chromophore in nonpigmented cutaneous tumors is hemoglobin

• Predominant vascular pattern also depends on volume of tumor and its proliferation pattern.

• Nodular component of tumors, develop through neovascularization phenomena

• Give rise to blood vessels with varying degrees of aberrant morphology.

Dermoscopic morphologic features of vessels according to their location in the skin

Vessels in normal skin; note dotted vessels corresponding to papillary dermal vessels and network of vessels corresponding to upper dermal plexus

Diagnostic procedure for a hypopigmented lesion.

Vessel morphology

Vessel distribution patterns / Architectural Arrangement

Vascular patterns seen in melanocytic lesions.

Vascular patterns seen in melanocytic lesions, clear-cell acanthoma, and basal cell carcinoma.

Intradermal melanocytic nevus with comma vessels scattered throughout the lesion.

A, Spitz nevus with dotted lesions distributed uniformly through the lesion. B, Spitz nevus with a greater variety of vascular patterns against a characteristic pink background.

A, Dysplastic nevus with predominant irregular linear vessels. B, Dysplastic nevus with dotted and comma vessels against a brownish background

A, Superficial spreading melanoma showing marked vascular polymorphism in the thick portion of the tumor. B, Detail of a milky-red globule containing vessels

Dotted vessels in the typical string of pearls arrangement seen in clear-cell acanthoma.

Bright red arborizing telangiectasias in sharp focus; a typical finding in basal cell carcinoma

Vascular patterns in keratinizing tumors

Vascular patterns in keratinizing tumors, sebaceous hyperplasia / molluscum contagiosum, and dermatofibroma

Hairpin vessels in seborrheic keratosis.

Crown vessels in a typical sebaceous hyperplasia lesion.

Bowen disease, glomerular vessels in a clustered distribution

Dotted vessels in a dermatofibroma.

Crown vessels in 2 molluscum contagiosum lesions.

Vascular patterns in vascular lesions and Kaposi sarcoma.

Rainbow pattern in Kaposi sarcoma.

Reddish-whitish areas, peripheral collarette, and rail lines in a pyogenic granuloma.

Oval lacunae characteristic of angioma serpiginosum

Vascular patterns in inflammatory lesions.

Vascular patterns in infectious lesions.

Dotted vessels combined with a scaling surface in a typical psoriatic plaque.

Dilated vessels in a string-like distribution in the center of a scar.

Diagnostic algorithm according to predominant vascular pattern.

Diagnosis Global Patterns Specific Local Features Additional Local Features

Confounding Features

Melanoma Multicomponent, reticular, globular, parallel-ridge, unspecific

Atypical pigment network, irregular dots/globules, irregular streaks, blue-whitish veil, irregular pigmentation, regression structures, dotted or linear irregular vessels

Hypopigmented areas, hairpin vessels, red globules

Homogeneous or starburst pattern; typical pigment network, regular dots/globules, regular streaks, milia-like cysts

Clark nevus Reticular, globular, homogeneous

Typical pigment network, regular dots/globules, regular diffuse or localized pigmentation, hypopigmented areas

Regular streaks, regression structures

Multicomponent pattern; atypical pigment network, irregular dots/globules, irregular streaks, irregular pigmentation, dotted vessels

Unna and Miescher nevi

Globular, cobblestone, reticular, homogeneous, unspecific

Regular dots/globules, exophytic papillary structures, typical pseudonetwork, comma vessels

Comedo-like openings, milia-like cysts

Multicomponent pattern; irregular pigmentation

Diagnosis Global Patterns Specific Local Features Additional Local Features

Confounding Features

Reed and Spitz nevi Starburst, globular, multicomponent

Regular streaks, regular diffuse pigmentation, reticular blue-whitish veil, regular dots/globules

Dotted vessels, typical pigment network

Reticular pattern; atypical pigment network, irregular dots/globules, irregular streaks, irregular pigmentation

Recurrent nevus Multicomponent, homogeneous, unspecific

Irregular pigmentation, irregular streaks, white areas

Atypical pigment network, irregular dots/globules

All local features mentioned in this row are commonly found in melanoma

Blue nevus Homogeneous Regular diffuse pigmentation

Hypopigmented areas Irregular diffuse pigmentation, arborizing vessels

Congenital nevus Multicomponent, cobblestone, globular, reticular

Regular dots/globules, typical pigment network, localized multifocal hypopigmentation, regular pigmentation

Milia-like cysts, comedo-like openings, exophytic papillary structures

Localized irregular pigmentation, regression structures

Diagnosis Global Patterns Specific Local Features Additional Local Features

Confounding Features

Combined nevus Multicomponent, homogeneous, globular, reticular

Typical pigment network, regular dots/globules, localized regular pigmentation

Hypopigmented areas, exophytic papillary structures

Atypical pigment network, localized or diffuse irregular pigmentation

Lentigo Reticular Typical pigment network or pseudonetwork, regular diffuse pigmentation

Milia-like cysts, regular dots/globules

Atypical pigment network, irregular pigmentation

Vascular lesions Lacunar, globular, homogeneous

Red lacunas, diffuse or localized structureless reddish-black to reddish-blue pigmentation

Parallel pattern, regular dots/globules, whitish-yellowish keratotic areas

Multicomponent pattern; irregular dots/globules, whitish veil

Diagnosis Global Patterns Specific Local Features Additional Local Features

Confounding Features

Labial and genital melanosis

Unspecific, parallel Regular diffuse pigmentation, typical pigment network

Regular streaks Atypical pigment network, irregular pigmentation

Basal cell carcinoma Unspecific, multicomponent, globular

Leaf-like areas, irregular blue-gray dots/globules, arborizing vessels

Milia-like cysts, hairpin vessels

Irregular gray-bluish pigmentation

Seborrheic keratosis Unspecific, globular, reticular, homogeneous

Milia-like cysts, comedo-like openings, exophytic papillary structures, regular diffuse pigmentation, hairpin vessels

Typical pigment network, hypopigmented areas, dotted vessels, gyri and sulci, whitish-yellowish horn masses

Multicomponent pattern; irregular pigmentation, regression structures, irregular dots/globules

Dermatofibra Reticular, unspecific, multicomponent

Annular pigment network, central white patch

Localized pigmentation or crusting, regular dots/globules, erythema

Irregular white areas

ABCD rule of dermoscopy (Modified according to Stolz 1994)Criterion Description Score Weight

factorAsymmetry In 0, 1, or 2 axes; assess not only contour, but also colors

and structures0-2 X 1.3

Border Abrupt ending of pigment pattern at the periphery in 0-8 segments

0-8 X 0.1

Color Presence of up to six colors 1-6 (white, red, light-brown, dark-brown, blue-gray, black)

1-6 X 0.5

Differential structures

Presence of network, structureless or homogeneous areas, streaks, dots, and globules

1-5 X 0.5

Total DermoscopyScore (TDS)

Interpretation

<4.75 Benign melanocytic lesion

4.8-5.45 Suspicious lesion; close follow-up or excision recommended

>5.45 Lesion highly suspicious for melanoma

Menzies scoring methodTo make a diagnosis of melanoma, 2 negative aspects (negative features) must be absent from the lesion and 1 or 2 positive aspects (from 1 of the 9 positive features) must be present.

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