Dermoscopic structures (full text)

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Main PageHistopathological correlationDermoscopic structures (full text)
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 Authored by: Ralph P. Braun     ·  Katrin Kerl

 Keywords:   dermoscopy · dermoscopic structures · melanoma
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Description Chapter provides an overview and linksThis glossary term has not yet been described. to all dermoscopyThe examination of [skin lesions] with a 'dermatoscope'. This traditionally consists of a magnifier (typically x10), a non-polarised light source, a transparent plate and a liquid medium between the instrument and the skin, and allows inspection of skin lesions unobstructed by skin surface reflections. Modern dermatoscopes dispense with the use of liquid medium and instead use polarised light to cancel out skin surface reflections. structuresThis glossary term has not yet been described. such as pigment networkGrid-like pattern consisting of interconnecting pigmented lines surrounding hypopigmented holes., globules etc.
Author(s) Ralph P. Braun · Katrin Kerl
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Pigment NetworkThis glossary term has not yet been described.

The pigment networkThis glossary term has not yet been described. consists of a grid of intersecting pigmented “linesstreaksThis glossary term has not yet been described.” forming a honeycomb pattern. The anatomic basis of the pigment network is melanin in keratinocytes or in melanocytes along the DEJ, representing the way the rete ridgeThis glossary term has not yet been described. pattern of the epidermis appears when viewed in the horizontal plane. The less-pigmented “holes” of the network correspond to tips of the dermal papillae and the overlying suprapapillary plates of the epidermis. A wide diameter of dermal papillae would correspond dermoscopically to wider network “holes,” whereas narrow dermal papillae would result in a denser sieve of the grid. The pigment network in melanocyticThis glossary term has not yet been described. lesions is further characterized as typical or atypical.

Network schematic-42.jpg

Typical networkNetwork with minimal variability in the color thickness and spacing of the lines; symmetrically distributed

The typical networkNetwork with minimal variability in the color thickness and spacing of the lines; symmetrically distributed is regularly meshed and composed of lines that are relatively uniform in width and homogenous in colorColor (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, yellow, purple, or blue.; the lines often become gradually thinner and fainter in pigmentation at the lesion’s periphery:

Network schematic.jpg

An example of a typical pigment networkNetwork with minimal variability in the color, thickness, and spacing of the lines; symmetrically distributed delicate network light brown, thin network lines clinically and dermoscopically:

Reguler network.jpg

On histopathologyThis glossary term has not yet been described., the lines of the typical network correspond to pigment in the rete ridgesEpidermal extensions that project into the underlying dermis, that are relatively uniform in width and equidistant from each other.

Histology network.jpg

The typical network usually corresponds to the junctional component of a nevusThis glossary term has not yet been described.. However, reticulation can also be seen in darkly pigmented normal skin and in heavily pigmented rete ridges as encountered in dermatofibromas.

Atypical networkNetwork with increased variability in the color, thickness, and spacing of the lines of the network; asymmetrically distributed; gray color

The atypical networkNetwork with increased variability in the color, thickness, and spacing of the lines of the network; asymmetrically distributed; gray color is irregularly meshed with lines that vary in width and degree of pigmentation and with “holes” that are heterogeneous in area and shape. An atypical network shows foci with broader and darker pigmented lines; the network often ends abruptly at the lesion’s periphery. An atypical network within a lesion may also appear perturbed and broken up, a finding referred to as “branched streaksBroadened or widened network with broken lines and incomplete connections”.

Atypical network31.jpg

An example of an atypical pigment networkNetwork with increased variability in the color, thickness, and spacing of the lines of the network; asymmetrically distributed; gray color clinically and dermoscopically:

Atypical network.jpg

On histolopathology, the irregular lines of an atypical network correspond to variation in the width, length, and spacing of the rete ridges due to variation in the size, spacing, and tendency to confluence of melanocytic nests. Rete ridgesEpidermal extensions that project into the underlying dermis that are elongated and widened by larger junctional nests of melanocytes would appear as darker and wider lines on dermoscopy. The atypical network is often seen in melanomaThis glossary term has not yet been described. and dysplastic neviThis glossary term has not yet been described..

PseudonetworkA structureless pigment area interrupted by non-pigmented adnexal openings

The anatomy of the rete ridge pattern of the faceis a central body region of sense and is also very central in the expression of emotion among humans and among numerous other species. differs from that of non-facial skinThis glossary term has not yet been described., and is usually flatter. Accordingly, the pigment network is usually absent in these locations and is replaced by a pseudonetworkA structureless pigment area interrupted by non-pigmented adnexal openings pattern. The "holes" in the pigmented epidermis correspond histologically to adnexal openings, such as sebaceous glands, hair follicles or sweat glands.

A pseudonetwork sketch:

Pseudonetwork schematic 23.jpg

Clinical and dermoscopic imagesA representation of a person, animal or thing, photographed, painted or otherwise made visible. of pseudonetwork:

Nevus face.jpg

Histologically, adnexal openings are responsible for the "holes" in the pigment reticulation:

Histology nevus face.jpg

Structureless Areas

Areas within a lesion that are devoid of any network or other structures, such as globules or regression structures (i.e., scars, pepperingGray dots, granularityThis glossary term has not yet been described., or blue-white veil over flat areas), are called “structureless areas”. Their size should be at least 10% of the lesions's total surface area. Structureless areas can be hypopigmentedThis glossary term has not yet been described., hyperpigmented or regularly pigmentedThis glossary term has not yet been described..

Hypopigmented structureless areas

Hypopigmented structureless areas have a lighter pigment compared with the rest of the lesion; however, they manifest the same or slightly more pigment compared with the surrounding normal skin (N.B.: structureless areas that are hyperpigmented are called blotches). Focal structureless areas within a lesion are a common finding in neviThis glossary term has not yet been described..

Nevus central hypopigmentation.jpg

In contrast, focal tan to light brown structureless areas at the periphery of a melanocytic lesion is commonly associated with melanoma. Peripherally located structureless areas in melanoma tend to have a light brown to fawn color and tend to end abruptly at the edge of a lesion. Histologically, these areas are characterized by flattening of the DEJ (loss of the undulating pattern of rete ridges and dermal papillae) and scattering of atypical melanocytes in suprabasal epidermal layers (i.e., pagetoid cells).


Hyperpigmented structureless areas (Blotches)

A blotchDark structureless areas is defined as an area with a size that is at least 10% of the lesion’s surface area and is heavily pigmented. In a blotch the melanin pigment is often present throughout the skinThis glossary term has not yet been described., including the stratum corneum, epidermis, and the dermis. The dark pigment in a blotch visually obscures the ability to discern any underlying structures. Blotches can be regular or irregular.

Regular hyperpigmented structureless areaThis glossary term has not yet been described. (BlotchDark structureless areas)

Peripheral reticuler central hyperpigmentation schematic.jpg

Regular blotches are defined as those that display symmetry, regular borders,homogenous dark hue, and are located within the center of the lesion. A pigment network often surrounds a regular blotchOne blotch within center of lesion and surrounded by network. Regular blotches are associated with nevi.

Regular blotch.jpg

Regular blotches can be seen in “activated” nevi and are attributed to heavy melanin concentrations in the stratum corneum. Because the pigment is concentrated in the stratum corneum, it can easily be stripped off using a tape-stripping procedure, thereby revealing underlying structures.


Irregular hyperpigmented structureless areablotch If centric hypermelanotic Clark (“dysplastic”) nevus if eccentric melanoma (Blotch)

Irregular blotches are defined as those that are asymmetric, have irregular contours, are located off center, and/or display multiple dark hues (i.e., heterogenous dark hues). Irregular blotches are associated with melanoma.

Atypical blotch 37.jpg
Irregular blotch.jpg
Irregular blotch histopathology.jpg

DotsDots are small, round structures of less than 0.1 mm in diameter that have a red color when corresponding to blood vessels; however, when due to melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effect).

Dots are small, round structures of less than 0.1 mm in diameter that correlate with blood vesselsare the part of the circulatory system, and microcirculation, that transports blood throughout the human body or melanin pigment. When blood vessels appear as dotsDots are small, round structures of less than 0.1 mm in diameter that have a red color when corresponding to blood vessels; however, when due to melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effect)., their color is red; however, when the underlying structure is melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effectCaused by light scattering by particles in a medium. The longer-wavelength light is more transmitted while the shorter-wavelength light is more reflected via scattering.). Black dots are often due to melanin pigment accumulation in the stratum corneum, but can also be due to vertical stacking of pigment within the epidermis or due to heavy aggregates of melanin in small clusters of melanocytes or keratinocytes located in the upper layers of the epidermis (just below the stratum corneum). Black dots that are in the stratum corneum are usually found overlying the grid lines of the pigmented network and they can easily be tape stripped off the skin. Brown dots are often associated with focal melanin accumulations at the DEJ or spinous layer and they usually correspond histologically to small junctional melanocytic nests. The dots, resulting from nevus nests located at the tips of rete ridges, tend to be situated overlying the network lines. Less frequently, brown dots correspond to melanocytic nests located in the skin below the stratum corneum or even within the stratum corneum. The nests present within the stratum corneum are probably in the process of being extruded from the skin via trans-elimination. Brown dots corresponding to small melanocytic nests situated in the papillary dermis appear as dots situated within the holes of the network. These so-called target networks with dots/globules or halo dots/globules are a common finding in congenital melanocytic nevi. Although on rare occasions brown dots can be tape stripped off the skin, most brown dots cannot be removed via tape strippingThis glossary term has not yet been described.. Black or brown dots may appear after acute ultraviolet exposure; however, these dots tend to disappear over time. It is interesting to note that many non–ultraviolet-induced dots that are successfully tape stripped off the skin reappear with time.

Gray-blue dots (also called granules or peppering) are due to fine melanin particles within melanophages or as extracellular “dust” in the superficialThis glossary term has not yet been described. dermis; this feature is associated with regressionThis glossary term has not yet been described..

Dots 28.jpg

Regular dotsDots clustered at the center of the lesion, or located on the network lines (also called target network)

Dots clustered at the center of the lesion, or located on the network lines (also called target network)

Regular dots 24.jpg
Dots.jpg

Irregular dotsAny distribution of dots other than dots as described for regular dots.

Irregular dots tend to be heterogenous in size, shape and color and are frequently found at the periphery of a given lesion or scattered throughout the lesion.

Dots schematic 24.jpg

GlobulesThis glossary term has not yet been described.

Globular pattern schematic.jpg
Globules26.jpg
Globules are symmetrical, round to oval, well-demarcated structures with a diameter that is larger than 0.1 mm. They usually correspond to nests of pigmented benignis any condition that is harmless in the long run or malignantThis glossary term has not yet been described. melanocytes situated in the lower epidermis, at the DEJ, or in the papillary dermis. On occasion globules may correspond to large clumps of melanin, melanophages, or pigmented milia cysts. Like dots, the color of globules may be brown, black, blue-gray, or red. The significance of these colorsThis glossary term has not yet been described. is the same as discussed for dots. Both dots and globules may occur in nevi as well as in melanoma. In nevi, the globules are uniform in size, shape, and color (mostly brown), and are either: (1) evenly distributed in the lesion; (2) mostly present at its center, surrounded by a network; (3) circumstantially along the entire perimeter of the nevus; or (4) uniformly distributed throughout the nevus.
Globules.jpg
Globules histology.jpg

In melanomas, globules and dots vary in size, shape, and color, are unevenly distributed in the lesion, and are frequently found focally at the periphery of lesions. Because both dots and globules frequently correlate with nests of melanocytes, they are often described for simplicity and reproducibility as a combined term “dots and globulesThis glossary term has not yet been described.”.


Streakslines radial (always at periphery) streaks Reed nevus melanoma recurrent nevus

Streaks are linear pigmented projections seen at the periphery of lesions. Both pseudopods (streakslines radial (always at periphery) streaks Reed nevus melanoma recurrent nevus with bulbous projections at their tips) and radial streamingRadial linear extensions at the lesion edge (streaks without bulbous projections at their tips) are considered to be streaks. Streaks in melanoma are usually observed only focally and asymmetrically at the lesion’s periphery and reflect the radial growth phase of the tumor. On the other hand, streaks that are distributed symmetrically around the entire perimeter of the lesion are seen mostly in pigmented spindle cell nevi (Spitz or Reed).

Streaks schematic 25.jpg

Histologically, streaks represent confluent junctional nests of melanocytes. Pseudopods are finger-like projections of dark pigment (brown to black) at the periphery of the lesion. They have small knobs at their tips, and are connected to either a central pigment network or central pigmented blotch. To be considered pseudopods the bulbous knobs must have a maximum diameter that is larger than the network from which it originates. Menzies and colleagues found pseudopods to be one of the most specific features of superficially spreadingThis glossary term has not yet been described. melanoma. On histopathology, pseudopods correspond to junctional confluent nests of melanocytes at the periphery of the lesion. Confluence of nests is also a criterion in histopathology, typical for dysplastic nevi or malignant melanoma. Depending on which area of the pseudopod is sectioned on histologyThis glossary term has not yet been described., the pathologist will see this structure either as a circular cluster of cells of varying diameters or as an oval-shaped cluster of cells. Only if the pathologyThis glossary term has not yet been described. section passes exactly through the longitudinal axis of a pseudopod will the pathologist be able to recognize this structure as an elongated tubular cluster of cells.

Pseudopod histology.jpg

Needless to say, the statistical probability of this happening is very low unless of course the pathologist uses dermoscopy at the grossing table to orient and oversee the step sectioning process. On occasion, peripheral globulesThis glossary term has not yet been described. and pseudopods can look similar to each other at first glance. However, with peripheral globules one will observe a small clear space separating the globuleThis glossary term has not yet been described. from the main tumor mass. These peripheral globules are presumed to correspond to junctional melanocytic nests at the tips of rete ridges and they are usually associated with growing/enlarging nevi. In contrast, pseudopods emanate from, and are directly connected to, the main tumor mass through a stalk. Radial streamingRadial linear extensions at the lesion edge appears as radial parallel linear extensions at the periphery of the lesion. On histopathology, radial streaming also correlates with confluent junctional nests of pigmented melanocytes.

Regular streaks.jpg

Irregular pseudopods .jpg

Negative Pigment Network

The “negativeThis glossary term has not yet been described.” of the pigmented network (also known as reverse or inverse network) consists of relatively lighter areas comprising the apparent grid of the network and relatively darker areas filling the apparent “holes”. The lighter grid lines tend to be serpiginous and the darker areas, when viewed in isolation, resemble elongated tubular or curved globules. Histopathologically, the negative networkSerpiginous interconnecting broadened hypopigmented lines that surround elongated and curvilinear globules. appears to correspond to thin elongated rete ridges accompanied by large melanocytic nests within a widened papillary dermis or to bridging of rete ridges. Although the negative network is highly specific for melanoma (95% specific), it can also be found in some Spitz neviThis glossary term has not yet been described. and rarely in other nevi, such as congenital neviis a type of melanocytic nevus (or mole) found in infants at birth. This type of birthmark occurs in an estimated 1% of infants worldwide; it is located in the area of the head and neck 15% of the time.. In congenital nevi, the negative pigmented network is usually diffuse and symmetrical in its distribution. In contrast, the negative pigmented network seen in melanoma is often focal and asymmetrically distributed.

Negative network schematic 32.jpg

Shiny white structuresThis glossary term has not yet been described.

Bright, white, shiny appearing structures that are visible under polarized dermoscopy and can take on different morphologies, including: shiny white streaksWhite lines that appear parallel and perpendicular to each other on polarized dermoscopy, shiny white blotches and strandsWhite structures in the form of circles, oval structures, or large structureless areas that are bright-white longer and less well defined lines oriented parallel or distributed haphazardly, or forming blotches (shiny white clods). Seen only under polarized dermoscopy. (shiny white areasThis glossary term has not yet been described.), and rosettesFour bright white dots or clods arranged together as a square (or a four leaf clover) [1]. Some authors don't make the distinction between them and refer to all of them as "shiny white structuresThis glossary term has not yet been described.".

Shiy white structures schematic 28.jpg
  • Shiny white streaksWhite lines that appear parallel and perpendicular to each other on polarized dermoscopy

Christalline structures are white shiny linear streaks that are seen under polarized dermoscopy, but not under nonpolarized dermoscopy. The white streaks are oriented parallel, and sometimes also orthogonal (perpendicular) to each other. Chrysalis structuresolt term for Chrysalis / Cristalline Structures can be seen in scars, dermatofibromas, basal cell carcinomas, and also in melanomas and Spitz nevi. These structures correlate histopathologically with altered collagen in the dermis (fibrosis). The birefringent properties of collagen bundles cause rapid randomization of polarized lightThis glossary term has not yet been described.. This is the reason collagen appears bright white and more conspicuous under polarized dermoscopy [2].

An example of shiny white lines as they appear in polarized (right image) as opposed to non-polarized dermoscopy (left image):

Npd vs pd blue veils.JPG

  • Shiny white blotches and strandsWhite structures in the form of circles, oval structures, or large structureless areas that are bright-white longer and less well defined lines oriented parallel or distributed haphazardly, or forming blotches (shiny white clods). Seen only under polarized dermoscopy. / Shiny white areasThis glossary term has not yet been described.

These are discrete, white shiny clods (blotches) or larger structureless areas or long thick or thin lines, randomly distributed or parallel, and not orthogonally oriented (Strands). Like shiny white streaks these structures have been associated with collagen alterations, such as fibrosis, in the underlying stroma [3].

  • RosettesFour bright white dots or clods arranged together as a square (or a four leaf clover)

Rosettes (also known as ‘four-clod dots’) are defined as four white points, arranged as a four leaf clover. They are not lesion-specific and are described in many tumoral and inflammatory lesions, including: scars, dermatofibromaDermatofibromas are hard solitary slow-growing papules (rounded bumps) that may appear in a variety of colours, usually brownish to tan; they are often elevated or pedunculated. A dermatofibroma is associated with the dimple sign; by applying lateral pressure, there is a central depression of the dermatofibroma., actinic keratosisActinic keratosis (also called solar keratosis and senile keratosis; abbreviated as AK) is a pre-cancerous patch of thick, scaly, or crusty skin., squamous cell carcinomaThis glossary term has not yet been described. and melanoma and more. Smaller rosettes are mainly caused by polarizing horny material at infundibular level in adnexal openings and larger rosettes mainly by concentric perifollicular fibrosis [4].

Regression StructuresThis glossary term has not yet been described.

Regression structuresThis glossary term has not yet been described. appear dermoscopically as:

  • white scar-like depigmentationThis glossary term has not yet been described. (lighter than the surrounding skin)
  • “peppering” (speckled multiple blue-gray granules)

On histopathology fully evolved regression shows fibrosis and melanosis (infiltrate of melanophages), and sparse lymphocytic infiltrates. The normal undulating DEJ pattern formed by rete ridges and dermal papillae is attenuated to completely Flattened. Regression structures consisting of both scar like depigmentation and peppering (granularity) should raise suspicion for melanoma. Regression structures consisting of only peppering can be seen in melanoma, lichen planus like keratosisThis glossary term has not yet been described. and nevi. In lichen planus like keratosis the granularity tends to be coarse and diffusely distributed. In melanocytic lesions the granularity tends to be finer and focally distributed.

White scar-like depigmentationThis glossary term has not yet been described.

corresponds to a white discoloration of the lesion, which is lighter than the surrounding normal skin. On histopathology, this dermoscopic structure correlates with fibrosis.

Scarlike depigmentation peppering 28.jpg

GranularityThis glossary term has not yet been described.

Granularity (also known as “peppering”) is defined as accumulation of multiple very small (<0.1 mm), nondescript, blue-grey dots. If a large area shows dense, confluent granularity, it is difficultneeding much effort or skill to accomplish to distinguish from blue-white veil, however, clinically, granularity often is seen in macular portions of the lesion, while blue-white veil is seen in palpable areas. Histopathologically, granularity correlates with melanin in the superficial dermis, either as fine melanin particles in melanophages or extracellular “dust-like” particles. When granularity is encountered in nevi it tends to encompass less than 10% of the lesion’s surface area. In contrast, in melanoma the granularity often encompasses more than 50% of the lesion’s surface area.

Confluent peppering scarlike 27.jpg

Blue-White Veil

Blue-white veil is confluent blue pigmentation with an overlying white “ground-glass” haze. In melanoma, the bluewhite veil does not occupy the entire surface area of the lesion, but rather is present as a focal, ill-defined area. Histopathologically, this dermoscopic structure corresponds to an aggregation of heavily pigmented cells (melanocytes and/or melanophages) or melanin in the dermis (blue color) in combinationThis glossary term has not yet been described. with compact orthokeratosis . At times, it is difficult to distinguish between regression structuresThis glossary term has not yet been described. (namely melanosis) and blue-white veil by dermoscopy because both structures display blue-white color. However, examining the lesion without dermoscopy can helpRefers to giving assistance or support to others for mutual benefit differentiate between blue-white color due to regression versus due to deep melanocytes. In regression the surface contour will be flat (macular) and in blue-white veil the surface will be raised and palpable. In melanoma the blue-white veil is nonuniform in color and is present focally within the lesion. In contrast, the blue-white veil has a uniform steel-blue color in blue nevi and it occupies the entire surface area of the lesion.

Blue whitish veil 26.jpg

Vascular Structures

In recent years, more attention has been given to the vascular patternsThis glossary term has not yet been described. of pigmented and nonpigmented lesions. The increased availability of dermoscopes using polarized light allow for the inspection of a lesion without the need to contact the lesion. This prevents blood vessel compression, which in part helps in making the blood vessel morphologyThis glossary term has not yet been described. more conspicuous. A detailed description of the vascular structuresThis glossary term has not yet been described. can be found here Vascular structures.

File 29.10.17, 19 44 37.jpeg

Milia-like Cysts

Milia-like cystsThis glossary term has not yet been described. are round whitish or yellowish structures that are commonly, but not exclusively, seen in seborrheic keratosisThis glossary term has not yet been described.. They can also be seen in melanocytic nevi, especially those with a congenital pattern. Sometimes milia-like cystsThis glossary term has not yet been described. are pigmented and resemble globules. Milia-like cysts correspond to intraepidermal keratin horn pseudocysts.

Milia like cysts comedo like openings schematic new.jpg
Milia like cysts.JPG

Comedo-like Openings

Comedo-like openings[[Comedo like openings]] are commonly seen in seborrheic keratosis and rarely in melanocytic nevi with a congenital pattern, such as papillomatous nevi. They appear on dermoscopy as dark roundish structures, and clinically, can be appreciated as surface invaginations. Histopathologically, comedo-like openings[[Comedo like openings]] correspond to the concave, keratin filled, invaginations of the epidermis.

Comedo like opening1.JPG

Fissures and Ridges (“Brain-like" or "Cerebriform Appearance”)

Fissures (invaginations or sulci) are commonly seen in seborrheic keratosis and may also be seen in melanocytic nevi with congenital pattern. In essence, fissures are linear grooves in the epidermis and, like comedo-like openings, correspond to surface invaginations. A pattern that resembles “brain-like appearancelines, curved and thick to describe the pattern and fissures and ridges (former synonyms “gyry and sulci” and “fat fingers”) to describe the structural components of the pattern SK” or cerebriform appearance is created, with the grooves resembling “sulci” and the intervening ridges resembling surface“gyri”. Fissures correspond histopathologically to wedgeshaped, keratin-filled invaginations of the epidermis.

Milia like cysts comedo like openings schematic new.jpg
Fissures and Ridges.JPG

Fingerprint-like Structures

Some flat seborrheic keratosesThis glossary term has not yet been described. and solar lentiginesThis glossary term has not yet been described. can show tiny ridges running in parallel and producing a pattern that is reminiscent of fingerprints.

Untitled Artwork 24.jpg

Moth-eaten Border

Some flat seborrheic keratoses have concave borders so that the pigment ends with curved to semi-circular indentations, which has been compared to a moth-eaten garment.

Solar lentigo schematic 2.jpg

Leaf-like Areas

Leaf-like areasBrown to gray/blue discrete linear or bulbous structures coalescing at a common off center base creating structures that resemble a leaf-like pattern. are seen as brown to gray-blue discrete bulbous blobs that often form a pattern shaped like a leaf. They can sometimes appear as tan, broad, and fuzzy streaks at the periphery of a lesion. In the absence of a pigment network, they are highly suggestive of pigmented basal cell carcinomas.

Histopathologically, they represent dermal nodular aggregates of pigmented basal cell carcinomaThis glossary term has not yet been described..

Leaf like areas29.jpg

Spoke-wheel-like Structures

Spoke-wheel-like structures are well-circumscribed brown to gray-blue– brown radial projections that radiate out from a dark brown central hub. Sometimes the radial projections are not visible and instead one sees a concentric globule consisting of a round structure with a central darker hub, which is surrounded by a brown halo of pigment. In the absence of a pigment network, spoke-wheels are highly suggestive of basal cell carcinomais the most common skin cancer, and one of the most common cancers in the United States.[1] While BCC has a very low metastatic risk, this tumor can cause significant disfigurement by invading surrounding tissues.

Histopathologically, they correspond to the nests of basal cell carcinoma emanating from the undersurface of the epidermis; a common finding in superficial basal cell carcinoma.

Spoke wheel schematic 27.jpg

Large Blue-Gray Ovoid Nests

Ovoid nests are large, discrete, and well-circumscribed, pigmented ovoid areas, larger than globules. When a network is absent, ovoid nests are highly suggestive of basal cell carcinoma. Ovoid nests correspond on histopathology to dermal aggregates of pigmented basal cell carcinoma.

Blue gray ovoid nests and globules BCC schematic.jpg

Multiple Blue-Gray Non-aggregated Dots and Globules

Multiple blue-gray dots and globules are round, discrete, and well circumscribed structures that, in the absence of a pigment network, are highly suggestive of a basal cell carcinoma. These dots and globules usually do not form aggregates as seen in melanocytic lesions. They correlate with dermal aggregates of pigmented basal cell carcinoma and are similar to ovoid nests, but smaller.

Blue gray ovoid nests and globules BCC schematic.jpg

LacunaeThis glossary term has not yet been described.

Lacunae are defined as multiple, clustered, well-demarcated, red to maroon to blue blobs with a round to oval shape. If the lacunaeThis glossary term has not yet been described. are blueblack in color, then the lesion may be an angiokeratomais a benign cutaneous lesion of capillaries, resulting in small marks of red to blue color and characterized by hyperkeratosis. The lacunae correspond to cavernous dilated blood vessels.

Lacunae 27.jpg

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ReferencesThis is material contained in a footnote or bibliography holding further information.:
  1. Liebman et al.: White shiny structures: dermoscopic features revealed under polarized light. J Eur Acad Dermatol Venereol 2012;26:1493-7. PMID: 22035217. DOI.
  2. Verzi et al.: The diagnostic value and histologic correlate of distinct patterns of shiny white streaks for the diagnosis of melanoma: A retrospective, case-control study. J. Am. Acad. Dermatol. 2018;78:913-919. PMID: 29138058. DOI.
  3. Navarrete-Dechent et al.: Association of Shiny White Blotches and Strands With Nonpigmented Basal Cell Carcinoma: Evaluation of an Additional Dermoscopic Diagnostic Criterion. JAMA Dermatol 2016;152:546-52. PMID: 26792406. DOI.
  4. Haspeslagh et al.: Rosettes and other white shiny structures in polarized dermoscopy: histological correlate and optical explanation. J Eur Acad Dermatol Venereol 2016;30:311-3. PMID: 25786770. DOI.