vascular patterns, pigmentary patterns, Pattern analysis, Reticular pattern, Globular pattern, Homogenous pattern, Multicomponent, Pattern comparison, Lesion specific features , Dermoscopic structures of non-melanocytic lesions, Vessel distribution patterns / Architectural Arrangement , ABCD rule of dermoscopy

1. TUTORIAL PRESENTATION
DERMOSCOPY :
PIGMENT v/s VASCULAR
BY Dr. D R DHAKED

2. 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

3. 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,

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

5. Understanding of different dermoscopic features is
important to formulate a diagnosis

6. 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

7. • 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

8. Typical
globular
pattern in
a Clark
nevus,
compound
type
Typical reticular pattern in a Clark nevus
Dermatofibroma with reticular
pattern in anular distribution
Atypical reticular pattern in a melanoma in situ

9. Typical cobblestone pattern
in a papillomatous dermal Typical homogeneous
nevus (Unna nevus)
pattern in a blue nevus
Brownish-gray
homogeneous pattern
in a blue nevus
Brownish-gray
homogeneous
pattern in a
dermal nevus
Lacunar pattern in an
angiokeratoma
Lacunar pattern in an angioma

10. Typical starburst
pattern in a Reed
nevus
Parallelfurrow
pattern,
in an
acral
nevus
Multicomponent pattern in a congenital speckled
nevus (nevus spilus)
Multicomponent pattern in a malignant melanoma
lattice-like pattern, in an acral nevus

11. 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

12. 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

13. Black:
Black:
epidermal melanin thrombus
Grey: upper
dermal
melanophages
Blue:
deep dermal
melanin
White: regression White:
or scarring
keratin
Dark brown:
Tan:
junctional melanin junctional melanin
Purple:
vascularity or
bleeding
Yellow:
keratin
Red:
vascularity or
bleeding
Multiple colours
: melanoma

14. 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

15. Homogeneous,
symmetrical lesion
Symmetrical shape
& structure
Asymmetrical shape &
pattern (atypical naevus)
Homogeneous structure
with asymmetrical shape
Symmetrical shape,
asymmetrical pattern (melanoma)

16. 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

17. 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.

18. Ink-spot lentigo
Junctional naevus
Junctional naevus
Starburst pattern
Lentigo simplex
Solar lentigo
Solar lentigo
Junctional naevus
Compound naevus
Atypical naevus
Compound naevus
Interrupted network
Atypical naevus
Annular network
Typical or Regular pigment network
Atypical naevus
Spoke-wheel network

19. 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.

20. Dysplastic naevus Dysplastic naevus Recurrence after
excision
Melanoma
Melanoma
Melanoma
Atypical lentiginous
hyperplasia
Melanoma
Irregular pigment network: red arrows point to branched streaks, black arrows to
broadened network, asterisk to streaming, thin arrow to pseudopods

21. 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

22. 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

23. 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.

24. Dermoscopy of palmo-plantar melanocytic lesions
Parallel furrow
pattern
Lattice pattern
Lattice pattern
Fibrillar pattern
Mixed pattern
Fibrillar pattern
Dysplastic naevus
Fibrillar pattern
Parallel ridge
pattern
Melanoma

25. 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

26. Solar lentigo
Diffuse amorphous areas
Benign naevus
Benign naevus
Blue naevus
Irregular amorphous areas
Dysplastic naevus Melanoma
Melanoma
Melanoma Also has
irregular network

27. 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.

28. Dots and globules in benign lesions
Central dots
Scattered dots
Central globules
Uniform globules
Dermal naevus
Cobblestone
pattern
Compound naevus
Peripheral
globules
Atypical naevus
Eccentric globules
Dysplastic naevus
Diffuse blue/grey
dots
Lichenoid keratosis

29. Dots and globules in melanoma: yellow arrows
Black dots
Brown dots
Grey dots
Peripheral dots
Dots in basal cell carcinoma: yellow arrows
Dots may be seen in pigmented basal cell carcinoma and rarely in
seborrhoeic keratoses.

30. Dermoscopic structures of nonmelanocytic 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

31. 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

32. •
•
•
•
•
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 ‘spokewheel 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

33. 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

34. 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

35. 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

36. Fingerprint-like structures
• Descriptive term for tan or dark-brown, fine parallel cordlike 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 Fat fingers
Crypts in elevated centre of
lesion
Fat fingers

37. 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
Sharp cut-off all
cut-off: melanoma round: melanoma
Moth-eaten edge:
ephilis

38. 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

40. 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

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

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

43. Diagnostic procedure for a hypopigmented
lesion.

44. Vessel morphology

47. Vessel distribution patterns / Architectural
Arrangement

49. Vascular patterns seen in melanocytic lesions.

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

51. 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

52. 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

53. Vascular patterns in keratinizing tumors

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

55. Hairpin vessels in seborrheic keratosis.
Bowen disease, glomerular vessels in a
clustered distribution
Crown vessels in a typical sebaceous
hyperplasia lesion.

56. Crown vessels in 2 molluscum
contagiosum lesions.
Dotted vessels in a
dermatofibroma.

57. Vascular patterns in vascular lesions and Kaposi sarcoma.

58. Rainbow pattern in Kaposi sarcoma.
Reddish-whitish areas, peripheral collarette,
and rail lines in a pyogenic granuloma.
Oval lacunae characteristic of angioma
serpiginosum

59. Vascular patterns in inflammatory lesions.

60. Vascular patterns in infectious lesions.

61. Dotted vessels combined with a scaling surface Dilated vessels in a string-like distribution in
in a typical psoriatic plaque.
the center of a scar.

62. Diagnostic
algorithm
according to
predominant
vascular
pattern.

63. Diagnosis
Global Patterns
Melanoma
Clark nevus
Specific Local Features
Additional Local
Features
Confounding Features
Multicomponent,
Atypical pigment network,
reticular, globular,
irregular dots/globules,
parallel-ridge, unspecific irregular streaks, bluewhitish 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, milialike cysts
Reticular, globular,
homogeneous
Regular streaks,
regression structures
Multicomponent
pattern; atypical
pigment network,
irregular dots/globules,
irregular streaks,
irregular pigmentation,
dotted vessels
Comedo-like openings,
milia-like cysts
Multicomponent
pattern; irregular
pigmentation
Typical pigment network,
regular dots/globules,
regular diffuse or localized
pigmentation,
hypopigmented areas
Unna and Miescher Globular, cobblestone, Regular dots/globules,
nevi
reticular, homogeneous, exophytic papillary
unspecific
structures, typical
pseudonetwork, comma
vessels

64. Diagnosis
Global Patterns
Specific Local Features Additional Local
Features
Confounding Features
Reed and Spitz nevi
Starburst, globular,
multicomponent
Regular streaks, regular Dotted vessels, typical
diffuse pigmentation,
pigment network
reticular blue-whitish
veil, regular
dots/globules
Reticular pattern;
atypical pigment
network, irregular
dots/globules, irregular
streaks, irregular
pigmentation
Recurrent nevus
Multicomponent,
homogeneous,
unspecific
Irregular pigmentation, Atypical pigment
irregular streaks, white network, irregular
areas
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- Localized irregular
like openings, exophytic pigmentation,
papillary structures
regression structures

65. Diagnosis
Global Patterns
Specific Local Features Additional Local
Features
Confounding Features
Combined nevus
Multicomponent,
Typical pigment
Hypopigmented areas,
homogeneous, globular, network, regular
exophytic papillary
reticular
dots/globules, localized structures
regular pigmentation
Atypical pigment
network, localized or
diffuse irregular
pigmentation
Lentigo
Reticular
Typical pigment network Milia-like cysts, regular
or pseudonetwork,
dots/globules
regular diffuse
pigmentation
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 Multicomponent
dots/globules, whitish- pattern; irregular
yellowish keratotic areas dots/globules, whitish
veil

66. Diagnosis
Global Patterns
Specific Local Features Additional Local
Features
Confounding Features
Labial and genital
melanosis
Unspecific, parallel
Regular diffuse
pigmentation, typical
pigment network
Atypical pigment
network, irregular
pigmentation
Basal cell carcinoma
Unspecific,
multicomponent,
globular
Leaf-like areas, irregular Milia-like cysts, hairpin
blue-gray dots/globules, vessels
arborizing vessels
Seborrheic keratosis
Unspecific, globular,
Milia-like cysts, comedo- Typical pigment
reticular, homogeneous like openings, exophytic network,
papillary structures,
hypopigmented areas,
regular diffuse
dotted vessels, gyri and
pigmentation, hairpin sulci, whitish-yellowish
vessels
horn masses
Dermatofibra
Reticular, unspecific,
multicomponent
Annular pigment
network, central white
patch
Regular streaks
Irregular gray-bluish
pigmentation
Multicomponent
pattern; irregular
pigmentation,
regression structures,
irregular dots/globules
Localized pigmentation Irregular white areas
or crusting, regular
dots/globules, erythema

67. ABCD rule of dermoscopy (Modified according to Stolz 1994)
Criterion
Description
Score
Asymmetry
In 0, 1, or 2 axes; assess not only contour, but also colors 0-2
and structures
X 1.3
Border
Abrupt ending of pigment pattern at the periphery in 0-8 0-8
segments
X 0.1
Color
Presence of up to six colors 1-6 (white, red, light-brown, 1-6
dark-brown, blue-gray, black)
X 0.5
Differential
structures
Presence of network, structureless or homogeneous
areas, streaks, dots, and globules
X 0.5
1-5
Weight
factor
Total Dermoscopy
Score (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

69. Menzies scoring method
To 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.

70. THANK