I.3 Dermoscopic Examination

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I.3.1 Introduction

Dermoscopy (also known as epiluminescence microscopy, dermatoscopy, amplified surface microscopy) is an in-vivo method that has been reported to be a useful tool for the early recognition of melanoma and the differential diagnosis of pigmented lesions of the skin [1, 2]. its use increases diagnostic accuracy between 5 and 30%

over clinical visual inspection, depending on the type of skin lesion and the experience of the physician. This was confirmed by two recent evidence-based publications from a meta-analysis of the literature [3].

I.3.2 Physical Aspects

light is either reflected, dispersed, or absorbed by the stratum corneum due to its refraction in- dex and its optical density, which is different from air; thus, deeper underlying structures cannot be adequately visualized. The use of immersion liquids renders the skin surface translucent and reduces reflections, so that underlying structures will become visible. The application of a glass plate flattens the skin surface and provides an even surface. optical magnification is used for examination. Taken together, these optical means allow the visualization of certain epidermal, dermo-epidermal, and dermal structures. as immersion liquid we recom- mend the use of 60° alcohol (ethanol) which can Chapter I.3

Dermoscopic Examination

ralph P. Braun, Harold S. rabinovitz, Margaret oliviero,

alfred W. Kopf, Jean-Hillaire Saurat, luc Thomas

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Contents

I.3.1 introduction . . . 7

I.3.2 Physical aspects . . . 7

I.3.3 Equipment for Dermoscopy . . . 8

I.3.4 Dermoscopic Criteria . . . 9

I.3.4.1 Colors . . . 9

I.3.4.2 Blood Vessels. . . 9

I.3.5 Dermoscopic Structures . . . 11

I.3.5.1 Pigment Network . . . 11

I.3.5.2 Dots . . . 11

I.3.5.3 Globules . . . 11

I.3.5.4 Branched Streaks . . . .12

I.3.5.5 Streaks . . . .12

I.3.5.6 Structureless areas . . . .13

I.3.5.7 Blotches . . . .13

I.3.5.8 regression . . . .13

I.3.5.9 Blue-White Veil . . . .13

I.3.5.10 Milia-like Cysts . . . .13

I.3.5.11 Comedo-like openings (Crypts, Pseudofollicular openings) . . . .13

I.3.5.12 Fingerprint-like Structures . . . 14

I.3.5.13 Moth-Eaten Border . . . 14

I.3.5.14 Fissures and ridges (“Brain-like” appearance) . . . 14

I.3.5.15 leaf-like areas . . . 14

I.3.5.16 Spoke-Wheel-like Structures . . . 14

I.3.5.17 large Blue-Gray ovoid Nests . . . 14

I.3.5.18 Multiple Blue-Gray Globules . . . 14

I.3.6 Differential Diagnosis of Pigmented lesions of the Skin . . . .15

I.3.7 aBCD rule of Dermatoscopy [11, 12] . . . . .19

I.3.7.1 asymmetry . . . .19

I.3.7.2 Border. . . .19

I.3.7.3 Colors . . . .19

I.3.7.3 Dermoscopic Structures . . . .19

I.3.7.3.1 Seven-Point Checklist . . . .20

I.3.7.3.2 Menzies Method . . . .20

I.3.7.3.3 Three-Point Checklist . . . .21

references . . . .21

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R. P. Braun, H. S. Rabinovitz, M. Oliviero et al.

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be applied directly on the skin using an eye dropper bottle [4]. The advantages are that ethanol results in the best image quality and the least air inclusions. it evaporates immediately, does not have to be wiped off, and does not stain the patient’s clothing or underwear. in areas close to the eyes or to the mucosa, as well as for the examination of the nail apparatus, we rec- ommend instead the use of a gel (ultrasound gel, cosmetic gel, etc.). a cosmetic gel does not burn the eyes and, most importantly, it fills out very nicely the gap between the convex nail surface and the handheld device. as an alternative to the immersion technique, some devices use polarized light in order to reduce the surface reflections. This technique allows a faster examination of the patient, but if the patient has dry skin the use of immersion liquid is still required.

I.3.3 Equipment for Dermoscopy as mentioned, dermoscopy requires optical magnification and liquid immersion. Specially designed handheld devices with 10–20 times magnification are commercially available (Der- matoscope Delta 20, Heine, Herrsching, Ger- many; DermoGenius Basic, Biocam, regens- burg, Germany; Dermlite (3Gen, San Juan Capistrano, Calif.); see Fig. i.3.1). all devices mentioned above are devices of the second generation which have improved optics and illumi-

nation (lED) compared with the older devices [1]. The optic is designed in such a way that a lesion can be examined at distance from the skin.

This is an advantage, because the examination is much faster and it is more comfortable for both, the physician and the patient, if the lesion is, for example, on the face or the genital area.

Photographic documentation can be per- formed in different ways [1]: The digital camera is directly attached to a handheld dermatoscope (coupling adapters are available for most handheld devices). in this case, the camera uses the optics and the illumination of the handheld dermatoscope. Since the optics of the handheld devices are not designed to fit a camera, the dermoscopic image is always a bit blurred towards the periphery, but this is the most inexpensive way of taking dermoscopy images.

Dermoscopy attachments (lenses) are directly attached to digital cameras. Their optics and illumination are designed to fit digital cameras and they provide the best image quality. These lenses can only be used with digital cameras and not for the examination of patients. There are many different attachments available, but we mainly use the Dermlite Foto attachment (3GEN; Fig. i.3.1) or a Dermaphot lens (Heine, aG) which can be attached to digital Slr cameras. The attachments can be used with different cameras and the resolution depends on the digital camera used. This solution enables con- veniently taking images of excellent quality.

Fig. I.3.1. a choiceof handheld dermatoscopes of the latest generation (from left to right): DermoGenius Basic (Biocam); Delta 20 (Heine);

Dermlite ii pro Hr (3GEN);

and Dermlite Foto (3GEN) on a Coolpix 4500 (Nikon)

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Dermoscopic Examination Chapter I.3

Storage and retrieval remain tricky for both ways of photo documentation mentioned above, and by the end of the day one finds himself with a camera full of images which have to be attrib- uted to patients and stored in a way that they can be easily retrieved.

Systems for digital dermoscopy consist of a video camera which is linked directly to a computer. The lesion can be examined “live” on the computer screen. These systems offer physicians many more features than the previous solutions, such as the possibility of easy storage and retrieval of lesions, which is important for follow- up examinations of suspect lesions. This is a big advantage, because when the patient leaves the office, all images (lesions) are correctly stored and there is no additional work to be done. Some systems offer even the possibility of computer- assisted diagnosis and/or teledermoscopy. Since these systems use a video camera, the resolution is not as good as with a digital consumer camera and a dermoscopy attachment, but the image quality is very good on the computer screen.

Systems for digital dermoscopy offer many more features and can make life much easier, but their disadvantages are their high cost and their lack of portability.

I.3.4 Dermoscopic Criteria

The use of dermoscopy allows the identification of many different structures, colors, and blood vessels not seen by naked-eye examination.

I.3.4.1 Colors

Colors play an important role in dermoscopy.

Common colors are light brown, dark brown, black, blue, blue-gray, red, yellow, and white.

The most important chromophore of the skin, especially in melanocytic neoplasms, is melanin. The color of melanin as seen with dermoscopy depends on its localization in the skin. For

example, melanin appears black in the stratum corneum and the upper epidermis, light to dark brown in the epidermis, gray to blue-gray in the papillary dermis, and steel blue in the reticular dermis. Melanin appears to be blue when it is localized within the deeper parts of the skin, because the portions of the visible light with lon- ger wavelengths (red end of visible spectrum) are more dispersed than the portions with shorter wavelengths (blue-violet end of the spectrum). The color red is associated with either an increased number or dilatation of blood vessels, trauma, or neo-vascularization (see vascular pattern). The color white is often due to regression and/or scaring (see regression).

I.3.4.2 Blood Vessels

in recent publications, blood vessels have gained much more importance and their morphological aspect enables the clinician in many cases to make the diagnosis, especially in non-pigmented lesions and lesions of non-melanocytic origin.The following types of blood vessels have been described: red lagoons; hairpin vessels;

dotted vessels; “comma”-like vessels; glomerular vessels; string of pearls; crown vessels; corkscrew vessels; and arborizing vessels (Table i.3.1) [5]. an atypical vascular pattern, also called irregular (polymorphous) vessels, may include linear, dotted, or globular red vessels, irregularly distributed within the lesion. Some of the vascular patterns may be due to neo-vascularization. For the evaluation of blood vessels, there has to be as little pressure as possible on the lesion during the examination, because otherwise the vessels are simply compressed and will not be visible. The use of ultrasound gel for immersion helps to reduce the pressure. an excellent alternative is the use of non-contact polarized light examination as used in some handheld dermatoscopes.

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10 R. P. Braun, H. S. Rabinovitz, M. Oliviero et al.

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Table I.3.1. Vascular architecture of pigmented skin lesions. (From [5])

Morphological aspect Correlation

red lagoons Sharply demarcated globular

structures, red, violaceous, brownish, bluish, or black

Hemangiomas or angiokeratomas

Hairpin vessels Elongated vessels resembling

hairpins Fine and surrounded by whitish

halo, seborrheic keratosis, or keratinizing tumor

irregular and thick melanoma or Spitz nevus

Dotted vessels Small vessels resembling

the head of a pin Vertical vessels seen in Spitz nevus or melanoma

observed also in psoriasis and squamous cell carcinoma Comma-like

vessels resembling the shape

of a comma Compound or dermal nevus

Clusters of glomerular

vessels Small- and fine-coiled vessels Bowen’s disease

observed in melanoma and stasis dermatitis String of pearls Globular vessels following

a serpiginous distribution Clear cell acanthoma

Crown vessels radial wreath-like or individual vessels at the periphery of the tumor; white-yellow globules in the center of the tumor

Sebaceous gland hyperplasia

Corkscrew vessels irregular and thick-coiled

vessels Melanoma including melanoma

metastasis

arborizing vessels resembling the branches

of a tree Basal cell carcinoma

irregular poly-

morphous vessels Multiple vessels with different shapes including comma, dotted irregular lines, corkscrew, glomerular, and others

Melanoma

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Dermoscopic Examination Chapter I.3 11

I.3.5 Dermoscopic Structures

in this chapter we use the nomenclature as pro- posed by the Consensus Netmeeting on Der- moscopy with some revisions [6].

I.3.5.1 Pigment Network

The pigment network is a honeycomb-like network that consists of pigmented “lines” and hypopigmented “holes.” The reticulation (network) represents the rete ridge pattern of the epidermis. its histopathological correlation is either melanin pigment in keratinocytes, or in melanocytes along the dermo-epidermal junction. The hypopigmented holes in the network correspond to tips of the dermal papillae and the overlying supra-papillary plates of the epidermis.

The pigment network can be classified as typical or atypical. a typical network is relative- ly uniform, regularly meshed, homogeneous in color, and usually thinning out at the periphery (Fig. i.3.2). an atypical network is non-uniform, with darker and/or broadened lines and “holes”

that are heterogeneous in diameter and shape.

The lines are often hyperpigmented and may end abruptly at the periphery.

I.3.5.2 Dots

Dots are small, round structures of less than 0.1 mm in diameter which may be black, brown, gray, or blue-gray. Black dots are due to pigment accumulation in the stratum corneum and the upper part of the epidermis (see colors). Brown dots represent focal melanin accumulations at the dermo-epidermal junction. Gray-blue granules are due to tiny melanin structures in the papillary dermis. Gray-blue or blue granules are due to loose melanin, fine melanin particles, or melanin “dust” in melanophages, or exist freely in the deep papillary or reticular dermis.

I.3.5.3 Globules

Globules are round to oval, well-demarcated structures that may be brown, black, or gray.

They have a diameter larger than 0.1 mm and correspond to nests of pigmented melanocytes, clumps of melanin, and/or melanophages situated usually in the lower epidermis, at the dermo-epidermal junction, or in the papillary dermis.Both dots and globules may occur in benign as well as in malignant melanocytic prolifera- tions. in benign lesions, they are regular in size and shape and evenly distributed (frequently in the center of a lesion; Fig. i.3.2). in melanomas, they tend to vary in size, color, and shape and are frequently found in the periphery of lesions.

Fig. I.3.2. Clinical picture of a benign compound nevus.

Dermoscopy shows a regular pigment network (reticular architecture) at the periphery and regular globules (globular architecture) in the center of the lesion.

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I.3.5.4 Branched Streaks

Branched streaks are an expression of an al- tered, perturbed pigment network in which the network becomes broken up (see aBCD rule of Dermoscopy; Figs. i.3.3, i.3.4). Their pathologi- cal correlations are remnants of pigmented rete ridges and bridging nests of melanocytic cells within the epidermis and papillary dermis. This term is exclusively used in the aBCD rule of dermoscopy and should not be confounded with the term “streaks,” which is used in the 7-point checklist of dermoscopy.

Fig. I.3.3. Clinical image of a lesion which has criteria for melanoma on clinical examination. Dermoscopy shows an irregular pigment network but no other criteria for melanoma. Using the 7-point checklist this lesion would have a score of 2 and would be classified as non- melanoma

I.3.5.5 Streaks

Both radial streaming and pseudopods correspond histopathologically to intraepidermal or junctional confluent radial nests of melanocytes. This is why some authors prefer using the term “streaks” interchangeably with radial streaming or pseudopods.

Streaks can be irregular (unevenly distributed in melanoma) or regular (symmetrical radial arrangement over the entire lesion); the latter is found particularly in the pigmented spindle cell nevi (reed’s nevi).

Radial Streaming

radial streaming appears as radially and asymmetrically arranged, parallel linear extensions at the periphery of a lesion (Fig. i.3.4).

Fig. I.3.4. Clinical image of a melanoma. Dermoscopy shows atypical pigment network, irregular dots in the periphery, regression areas, irregular pigmentation, and irregular streaks (radial streaming)

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Pseudopods

Pseudopods represent finger-like projections of dark pigment (brown to black) at the periphery of the lesion. They may have small knobs at their tips, and are either connected to the pigment network or directly to the tumor body.

I.3.5.6 Structureless Areas

Structureless areas represent areas devoid of any discernible structures (globules, network, etc.).

They tend to be hypopigmented, which is due to the absence of pigment or diminution of pigment intensity within a pigmented skin lesion.

a structureless or hypopigmented area cannot be lighter than the surrounding skin and does not have signs of granularity (peppering) in its periphery.

I.3.5.7 Blotches

a blotch (black lamella) is a diffuse pigmentation of black to dark brown color which ob- scures underlying structures. it is due to a large concentration of melanin pigment localized throughout the epidermis and/or dermis visu- ally. a blotch can be regular, often in the center of a lesion (junctional nevus), or irregular (melanoma).

I.3.5.8 Regression

regression appears as white scar-like depigmentation (lighter than the surrounding skin) or “peppering” (speckled multiple blue gray granules within a hypopigmented area; see Fig. i.3.4). Histopathologically, regression shows fibrosis, loss of pigmentation, epidermal thinning, effacement of the rete ridges, and melanin granules free in the dermis or in melanophages scattered in the papillary dermis.

I.3.5.9 Blue-White Veil

Blue-white veil is an irregular, indistinct, confluent blue pigmentation with an overlying white ground-glass haze. The pigmentation cannot occupy the entire lesion and is found mainly in the papular part of the lesion. Histo- pathologically this corresponds to an aggrega- tion of heavily pigmented cells or melanin in the dermis (blue color) in combination with a com- pact orthokeratosis. Blue-white veil should not be confused with confluent peppering (granularity) in regression areas of melanomas; the latter is the dermoscopy aspect of (histopathological) melanosis. Both entities might have a similar dermoscopy aspect but do not have the same histopathological correlation. The blue- white veil is, together with pigment-network structures, a highly specific criterion for the diagnosis of melanoma.

I.3.5.10 Milia-like Cysts

Milia-like cysts are round whitish or yellowish structures which are seen mainly in seborrheic keratosis. They correspond to intraepidermal keratin-filled cysts and may also be seen in congenital nevi as well as in some papillomatous melanocytic nevi (Fig. i.3.5).

I.3.5.11 Comedo-like Openings (Crypts, Pseudofollicular Openings)

Comedo-like openings (pseudocomedos) are seen mainly in seborrheic keratosis (Fig. i.3.5) or in some rare cases in papillomatous melanocytic nevi. Histopathologically they correspond to keratin-filled invaginations of the epidermis.

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I.3.5.12 Fingerprint-like Structures Some flat seborrheic keratoses (also known as solar lentigines) can show tiny ridges running in parallel and producing a pattern which re- sembles fingerprints.

I.3.5.13 Moth-Eaten Border

Some flat seborrheic keratoses (mainly on the face) have a concave border so that the pigment ends with a curved structure. This has been compared to a moth-eaten garment.

I.3.5.14 Fissures and Ridges (“Brain-like” Appearance) Fissures are irregularly, linear keratin-filled de- pressions, commonly seen in seborrheic keratosis (Fig. i.3.5). They may also be seen in melanocytic nevi with congenital patterns and in some dermal melanocytic nevi. Multiple fissures might give a “brain-like” appearance to the lesion. This pattern has also been named “gyri and sulci” by some authors.

I.3.5.15 Leaf-like Areas

leaf-like areas (maple-leaf-like areas) are seen as brown to gray-blue discrete bulbous blobs, sometimes forming a leaf-like pattern. Their distribution reminds one of the shape of finger pads. in the absence of a pigment network, they are suggestive of pigmented basal cell carcino- mas.

I.3.5.16 Spoke-Wheel-like Structures Spoke-wheel-like structures are well-circumscribed brown to gray-blue-brown radial projections meeting at a darker brown central hub.

in absence of a pigment network, they are highly suggestive of basal cell carcinoma.

Fig. I.3.5. Clinical image of a pigmented seborrheic keratosis. Dermoscopy shows multiple milia-like cysts, pseudocomedos, some crypts (fissures), regular hairpin blood vessels, as well as a sharp demarcation

I.3.5.17 Large Blue-Gray Ovoid Nests ovoid nests are large, well-circumscribed, confluent, or near-confluent pigmented ovoid areas, larger than globules, and not intimately connected to a pigmented tumor body (Fig. i.3.6). When a network is absent, ovoid nests are highly suggestive of basal cell carcinoma.

I.3.5.18 Multiple Blue-Gray Globules Multiple blue-gray globules are round well-circumscribed structures which are, in the absence of a pigment network, highly suggestive of a basal cell carcinoma (Fig. i.3.6). They have to be

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differentiated from multiple blue-gray dots (which correspond to melanophages and melanin dust).

I.3.6 Differential Diagnosis

of Pigmented Lesions of the Skin The Board of the Consensus Netmeeting agreed on a two-step procedure for the classification of pigmented lesions of the skin (see Fig. i.3.7) [6].

The first step is the differentiation between a melanocytic and a non-melanocytic lesion.

once a lesion has been identified to be of melanocytic origin, it has to be determined in a second step whether the lesion is benign, suspicious, or malignant. This can be done with the help of different algorithms, which are discussed later.

For the first decision (melanocytic vs non- melanocytic) the following algorithm is used (Fig. i.3.8):

Steps 1-2: are pigment network, aggregated globules, branched streaks, homogenous blue pigmentation, or a parallel pattern (palms, soles, and mucosa) visualized? if this is the case, the lesion should be considered as a melanocytic lesion (Figs. i.3.2, i.3.3, i.3.4).

Step 3: if this is not the case, the lesion should be evaluated for the presence of comedo-like plugs, multiple milia-like cysts, and comedo- like openings, irregular crypts, light-brown fingerprint-like structures, or “fissures and ridges”

(brain-like appearance) pattern; if so, the lesion is suggestive of a seborrheic keratosis (Fig. i.3.5) [7].Step 4: if such is not the case, the lesion has to be evaluated for the presence of arborizing blood

Fig. I.3.6. a Clinical image of a partially pigmented basal cell carcinoma. b Dermoscopy shows arborized telangi- ectasia as well as an ovoid nest and multiple blue-gray dots and globules. c Clinical image of a pigmented basal

cell carcinoma. d Dermoscopy shows a spoke-wheel area, a blue-gray ovoid nest, a small area of ulceration, and multiple blue-gray dots and globules

a

c

b

d

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vessels (telangiectasias), leaf-like areas, large blue-gray ovoid nests, multiple blue-gray globules, spoke-wheel areas, or ulceration. if present, the lesion is suggestive of basal cell carcinoma (Fig. i.3.6) [8].

Step 5: if such is not the case, one has to look for red or red-blue (to black) lagoons. if these structures are present, the lesion should be considered as hemangioma or an angiokeratoma (Fig. i.3.9).

Step 6: if all the preceding questions were an- swered with “no,” the lesion should still be considered as melanocytic in order not to miss a melanoma.

once the lesion is identified to be of melanocytic origin, the decision has to be made as to whether the melanocytic lesion is benign, suspect, or malignant. To accomplish this, the following algorithms are most common:

Fig. I.3.7. Two-step procedure for the classification of pigmented skin lesions (modified)

Fig. I.3.8. algorithm for the decision of melanocytic vs non-melanocytic lesion according to the proposition of the Board of the Consensus Netmeeting (modified)

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1. Pattern analysis [9]

Pattern recognition has historically been used by clinicians and histopathologists to differentiate benign lesions from malignant neoplasms.

a similar process has been found to be useful with dermoscopy, and has been termed “pattern analysis.” it allows distinction between benign and malignant growth features. it was described by Pehamberger and colleagues based on the analysis of more than 7000 pigmented skin lesions [9]. Table i.3.2 shows the typical patterns of some common, pigmented skin lesions using pattern analysis.

2. Revised pattern analysis

The revised pattern analysis distinguishes between global patterns and local features [10].

The general appearance of Color, Architectural order, Symmetry of pattern, and Homogeneity (CaSH) are important components in benign le-

sions from melanoma. Benign melanocytic lesions tend to have few colors, architectural order, symmetry of pattern, and homogeneity. Melano- ma often has many colors, architectural disorder, asymmetry of pattern, and heterogeneity.

The reticular pattern or network pattern is the most common feature in melanocytic lesions. This pattern represents the junctional component of a melanocytic nevus.

another pattern is the so-called globular pat- tern. it is characterized by the presence of nu- merous “aggregated globules.” This pattern is commonly seen in a congenital nevus, superfi- cial type.

The cobblestone pattern is very similar to the globular pattern but is composed of closer aggregated globules, which are somehow angulat- ed, resembling cobblestones.

The homogeneous pattern appears as diffuse pigmentation, which might be brown, gray-blue, gray black, or reddish black. No pigment network or any other distinctive dermoscopy structures are found. an example is the homogenous steel-blue color seen in blue nevi.

The so-called starburst pattern is character- ized by the presence of streaks in a radial arrangement, which is visible at the periphery of the lesion. This pattern is commonly seen in reed nevi or Spitz’s nevi.

The parallel pattern is exclusively found on the palms and soles due to the particular anato- my of these areas.

The combination of three or more distinctive dermoscopic structures (i.e., network, dots, and globules, as well diffuse areas of hyper- and hy- popigmentation) within a given lesion is called multicomponent pattern. This pattern is highly suggestive of melanoma but might be observed in some cases in acquired melanocytic nevi and congenital nevi.

The term “lesions with indeterminate patterns” are dermoscopic patterns that can be seen in both benign and malignant pigmented lesions. Clinically and dermoscopically one cannot distinguish whether they are melanomas or atypical nevi.

in addition to the global features mentioned above, the local features (dermoscopic structures such as the pigment network, dots, and globules, etc.) are important to evaluate melanocytic lesions (Table i.3.3).

Fig. I.3.9. Clinical picture of a cherry angioma. Dermos- copy shows multiple red lagoons

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Table I.3.2. Pattern analysis. (Modified after [9])

Lentigo simplex Junctional nevus Compound nevus Dermal nevus Blue nevus regular pigment

network without interruptions

regular pigment network without interruptions

No criteria for

melanocytic lesion Steel blue areas regular border,

thins out at the periphery

regular border, thins

out at the periphery regular border, thins out at the periphery

No pigment network No pigment network Black dots over the

grids of the pigment network

Heterogeneous holes of the pigment network

Heterogenous holes of the pigment network

Brown globules ill defined

Brown-black globules at the center of the lesion

Brown globules Brown globules Homogenous colors White veils are possible Homogenous colors Homogenous colors Symmetric papular

appearance “Pseudonetwork” No pseu-

donetwork all criteria for

melanocytic lesion possible

“Comma”-shaped blood vessels Color heterogeneity

possible Melanoma atypical (Clarks)

nevus angioma Seborrheic keratosis Pigmented

BCC Heterogeneous

(colors and structures)

irregular pigment network with interruptions

No features of

melanocytic lesion No features for a

melanocytic lesion No features for melanocytic lesion asymmetry (colors

and structures) Heterogeneous holes No pigment network Pigment network

usually absent Maple-leaf- like pigmentation irregular pigment

network irregular border red, red-blue, or red-black lagoons (globules, saccules)

Milia-like cysts Telangiectasis

irregular border with abrupt peripheral margin

Heterogeneity

of colors abrupt border

cut-off Pseudofollicular

openings, comedo- like openings (plugs)

Tree-like blood vessels

Structureless areas Gray-white veil rough surface “Dirty” gray

brown to gray-black colors

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I.3.7 ABCD Rule of Dermatoscopy [11, 12]

The aBCD rule of dermatoscopy, described by Stolz et al. in 1994 [11], was based on an analysis of 157 pigmented skin lesions. it is based on a scoring system for melanocytic neoplasms that differentiates them into benign, suspicious, and malignant categories. This is accomplished by calculating a total dermoscopy score (Ta- ble i.3.4).

I.3.7.1 Asymmetry

The lesion is bisected by two lines that are placed 90° to each other. The first line attempts to bi- sect the lesion at the division of most symmetry and the other one is placed 90° to it. Symmetry takes into account the contour, colors, and structures within the lesion. lesions that are symmetric in both axes are given zero points.

Points for asymmetry are multiplied with a weighting factor of 1.3 to calculate the dermoscopy score.

I.3.7.2 Border

First the lesion is divided into eight equal pie- shaped pieces. Next, one counts the number of segments that have an abrupt perimeter cut-off;

thus, the points range from 0 to 8, which have to be multiplied with a weighting factor of 0.1.

I.3.7.3 Colors

Number the following colors present: light brown; dark brown; black; red; white; and blue- gray. The points will range from 1 to 6, which have to be multiplied with a weighting factor of 0.5.

I.3.7.3 Dermoscopic Structures

Number the following five structures: dots;

globules; structureless areas; network; and branched streaks. The points range from 1 to 6, which have to be multiplied with a weighting factor of 0.5.

Table I.3.3. Patterns of benign and malignant melanocytic lesions

Benign melanocytic lesions Malignant melanocytic lesions Dots Centrally located or situated right on the

network Unevenly distributed and scattered focally at

the periphery Globules Uniform in size, shape, and color

symmetrically located at the periphery, centrally located, or uniform throughout the lesion as in a cobblestone pattern

Globules which are unevenly distributed and when reddish in color are highly suggestive of melanoma

Streaks radial streaming or pseudopods tend to be

symmetrical and uniform at the periphery radial streaming or pseudopods tend to be focal and irregular at the periphery Blue-white veil Tends to be centrally located Tends to be asymmetrically located

or diffuse almost over the entire lesion Blotch Centrally located or may be a diffuse

hyperpigmented area that extends almost to the periphery of the lesion

asymmetrically located or there are often multiple asymmetrical blotches

Network Typical network that consists of light- to-dark uniform pigmented lines and hypopigmented holes

atypical network which may be non-uniform with black/brown or gray thickened lines and holes of different sizes and shapes Network

borders Either fades into the periphery or is

symmetrically sharp Focally sharp

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Table I.3.4. The aBCD rule of dermoscopy. (Modified after [11])

Points Weight factor Sub-score range

asymmetry Complete symmetry 0 1.3 0−2.6

asymmetry in one axis 1

asymmetry in two axes 2

Border Eight segments, one point for abrupt

cut-off of pigment 0−8 0.1 0−0.8

Color one point for each color: white; red;

light brown; dark brown; black; blue gray

1−6 0.5 0.5−3.0

Differential

structures one point for every structure: pigment network; structureless areas; dots;

globules; branched streaks

1−5 0.5 0.5−2.5

Total score range: 1.0–8.9

The individual points are multiplied with weighting factor which is specific for each criterion. The different sub-scores are then added together in order to obtain the total dermoscopy score (TDS). a lesion with a TDS <4.75 can be considered to be benign. a lesion with a TDS

>5.45 should be considered to be malignant and should be removed. lesions with a TDS between 4.75 and 5.45 should be considered to be suspicious and should be either removed or moni- tored.

I.3.7.3.1 Seven-Point Checklist

in 1998 argenziano and colleagues described a 7-point checklist based on the analysis of 342 pigmented skin lesions [13]. They distinguished three major criteria (atypical pigment network, blue-whitish veil, atypical vascular pattern) and four minor criteria (irregular streaks, irregular pigmentation, irregular dots/globules, regression structures; Table i.3.5). Each major criterion has a score of 2 points and each minor criterion has a score of 1 point. a minimum total score of 3 is required for the diagnosis of melanoma. The 7-point checklist was the first algorithm which compromised the vascular architecture of a lesion.

I.3.7.3.2 Menzies Method

in Menzies method for diagnosing melanoma, both of the following negative features have to be absent: single color (tan, dark brown, gray, black, blue, and red, but white is not considered) and “point and axial symmetry of pigmentation” (refers to pattern symmetry around any axis through the center of the lesion). This does not require the lesion to have symmetry of shape.

Table I.3.5. The 7-point checklist. (according to [6])

Criteria 7-point score

Major

atypical pigment network 2

Blue-whitish veil 2

atypical vascular pattern 2

Minor

irregular streaks 1

irregular pigmentation 1 irregular dots/globules 1 regression structures 1

(15)

in addition, at least one or more of the positive features that are described in Table i.3.6 has to be found.

I.3.7.3.3 Three-Point Checklist

The three-point checklist [15] is based on a sim- plified pattern analysis and is intended for use by non-experts as a screening technique. The three-point checklist does not differentiate between melanocytic and non-melanocytic lesions. its aim is to identify all potentially malignant lesions, including basal cell carcinoma and melanoma, with a high degree of sensitivity. re- markably, the sensitivity for detecting malignancy by non-experts using the three-point checklist has reached 96.3%; however, as is true for all screening techniques, the specificity achieved by non-experts was much lower (32.8%) than that achieved by experts (94.2%).

The three-point checklist requires the exam- iner to assess the lesion for only three dermoscopic criteria: (a) asymmetry; (b) atypical network; and (c) blue-white structures. The presence of two or three features suggests that the lesion under investigation is suspect for malignancy.

C Core Messages

■ Dermoscopy increases diagnostic accuracy by 5–30%

■ Features of skin lesions not seen by naked-eye examination can be visualized with dermoscopy:

1. Colors (brown, black, blue, blue-gray, red, yellow, and white) 2. Blood vessel types (red lagoons,

string of pearls, hairpin, dotted,

“comma”-like, glomerular, crown, corkscrew, arborizing, or irregular vessels)

3. architectural criteria (pigment network, dots, globules, branched streaks, streaks, structureless areas, blotches, regression, blue-white veil, milia-like cysts, comedo-like openings, fingerprint-like structures, moth-eaten borders, fissures and ridges, leaf-like areas)

■ Potentially malignant lesions tend to show two of the following three features: asymmetry; atypical network;

and blue-white structures (3-step checklist).

References

1. Marghoob aa, Braun rP, Kopf aW. atlas of dermoscopy. New York: Taylor Francis; 2004

2. Braun rP, rabinovitz HS, oliviero M, Kopf aW, Saurat JH. Dermoscopy of pigmented skin lesions.

J am acad Dermatol 2005; 52(1):109-121

3. Kittler H, Pehamberger H, Wolff K, Binder M. Diag- nostic accuracy of dermoscopy. lancet oncol 2002;

3(3):159-165

4. Gewirtzman aJ, Saurat JH, Braun rP. an evaluation of dermoscopy fluids and application techniques. Br J Dermatol 2003; 149(1):59-63

5. Malvehy J, Puig S, Braun rP, Marghoob aa, Kopf aW. Handbook of dermoscopy. First ed. london and New York: Taylor and Francis; 2006

6. argenziano G, Soyer HP, Chimenti S, Talamini r, Corona r, Sera F, et al. Dermoscopy of pigmented skin lesions: results of a consensus meeting via the internet. J am acad Dermatol 2003; 48(5 Pt 1):679–

693 Table I.3.6. The Menzies method. (according to [8])

Negative features

Point and axial symmetry of pigmentation Presence of a single color

Positive features Blue-white veil Multiple brown dots Pseudopods radial streaming Scar-like depigmentation Peripheral black dots−globules Multiple colors (five or six) Multiple blue/gray dots Broadened network

(16)

R. P. Braun, H. S. Rabinovitz, M. Oliviero et al.

I.3

7. Braun rP, rabinovitz H, Krischer J, Kreusch J, oliviero M, Naldi l, et al. Dermoscopy of pigmented seborrheic keratosis. arch Dermatol 2002;

138:1556–1560

8. Menzies SW, Westerhoff K, rabinovitz H, Kopf aW, McCarthy WH, Katz B. Surface microscopy of pigmented basal cell carcinoma. arch Dermatol 2000;

136(8):1012–1016

9. Pehamberger H, Steiner a, Wolff K. in vivo epiluminescence microscopy of pigmented skin lesions.

i. Pattern analysis of pigmented skin lesions. J am acad Dermatol 1987; 17(4):571–583

10. argenziano G, Soyer HP, Giorgio V de, Piccolo D, Carli P, Delfino M, et al. Dermoscopy a tutorial.

First ed. Milan: EDra; 2000

11. Stolz W, riemann a, Cognetta aB, Pillet l, abmayr W, Hölzel D, et al. aBCD rule of dermatoscopy: a new practical method for early recognition of malignant melanoma. Eur J Dermatol 1994;

4:521–527

12. Stolz W, Braun-Falco o, Bilek P, landthaler M, Burgdorf WHC, Cognetta aB. Color atlas of dermatoscopy, 2nd ed. Berlin: Blackwell Wissenschafts- Verlag; 2002

13. argenziano G, Fabbrocini G, Carli P, Giorgio V de, Sammarco E, Delfino M. Epiluminescence microscopy for the diagnosis of doubtful melanocytic skin lesions. Comparison of the aBCD rule of dermatoscopy and a new 7-point checklist based on pattern analysis. arch Dermatol 1998; 134(12):1563–1570 14. Menzies SW, Crotty Ka, ingvar C, McCarthy WH.

an atlas of surface microscopy of pigmented skin lesions: Dermoscopy, 2nd edn. roseville: McGraw- Hill; 2003

15. Soyer HP, argenziano G, Zalaudek i, Corona r, Sera F, Talamini r, et al. Three-point checklist of dermoscopy. a new screening method for early de- tection of melanoma. Dermatology 2004; 208(1):27–

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