Am Fam Physician. 2013;88(7):1-6
| Dermoscopic structures | Schematic illustration | Definition | Histopathologic correlation |
|---|---|---|---|
| Pigment network | Grid-like network consisting of pigmented lines and hypopigmented holes | Melanin in keratinocytes or melanocytes along the dermoepidermal junction | |
| Network lines correspond to the rete ridges | |||
| Holes correspond to the suprapapillary plate | |||
| Pseudonetwork | Diffuse pigmentation interrupted by adnexal opening | Pigment in the epidermis or dermis in which the rete ridges are attenuated | |
| Usually seen in facial lesions | |||
| Negative pigment network | Serpiginous interconnecting hypopigmented lines that surround irregularly shaped pigmented structures resembling elongated curvilinear globules | Remains unknown | |
| Presumed to be related to bridging of rete ridges or large melanocytic nests in the papillary dermis, resulting in compression of adjacent rete ridges; these nests may correspond to globules that are not spherical in shape | |||
| Aggregated globules | More than three clustered, well- demarcated, round to oval, symmetric structures, or three or more of these structures aligned at the lesion's perimeter | Nests of melanocytes at the dermoepidermal junction | |
| May be brown, black, or blue | |||
| Diameters are greater than 0.1 mm | |||
| Dots | Small, round structures of less than 0.1 mm in diameter | Aggregates of melanocytes or melanin granules | |
| May be black, brown, or blue-gray | |||
| Streaks (pseudopods and radial streaming) | Streaks are radial projections at the periphery of the lesion, extending from the tumor toward the surrounding normal skin; may be brown or black | Confluent junctional nests of melanocytes | |
| Pseudopods are streaks with finger-like projections with small knobs at the tips | |||
| Radial streaming is streaks without knobs at the tips | |||
| Peppering (or granularity) | Tiny, blue-gray granules | Melanin deposited as intracellular (mostly within melanophages) or extracellular particles in the upper dermis | |
| Structureless areas | Devoid of dermoscopic structures within the lesion and without manife sting any regression structures | Relative decreased concentration of melanin or flattening of rete ridges | |
| Tend to be tan to light brown, but have lighter pigment compared with the rest of the lesion | |||
| Peripheral light brown or tan structureless areas | Structureless areas (as above), located at the periphery of the lesion | Partial or complete flattening of the rete ridges | |
| Increased number of pigmented atypical melanocytes predominantly at the dermoepidermal junction | |||
| Diffuse scattering of melanocytes in the spinous layer of the epidermis | |||
| Blotches | Dark brown to black homogeneous areas of pigment that obscure visualization of any other structures | Aggregates of melanin in the stratum corneum or throughout all layers of the skin | |
| Regression structures | Include scar-like depigmentation (lighter than the surrounding uninvolved normal skin; appear shiny white under polarized dermoscopy) often combined with peppering; combination of scar-like depigmentation and peppering gives the appearance of a blue-white veil | Scar-like changes/white areas: thickened fibrotic papillary dermis | |
| Blue areas: correlate with melanosis type of regression | |||
| Blue-white veil | Confluent blue pigmentation with an overlying white ground-glass haze | Aggregation of heavily pigmented melanocytes or melanophages in combination with compact orthokeratosis of the stratum corneum | |
| White shiny structures (more conspicuous with polarized dermoscopy) | Rosettes: appear as four white shiny points creating a pattern reminiscent of a four- leaf clover A4 | Histopathologic correlation has not been fully explained | |
| Crystalline structures: short, white, shiny linear streaks that are often parallel or orthogonal to each other A5, A6 | Altered collagen or fibrosis in the dermis | ||
| White shiny areas: appear as larger structureless areas of shiny white color | Altered stromal matrix | ||
| Parallel pigment pattern | On volar skin (i.e., palms and soles) | Pigmented melanocytes in the furrows (crista limitants) or ridges (crista intermedia) on skin of palms and soles | |
| Parallel rows of pigmentation following the furrows (as seen in nevi) or ridges (as seen in melanoma) of the dermatoglyphics |
| Dermoscopic structures | Schematic illustration | Definition | Histopathologic correlation |
|---|---|---|---|
| Milia-like cysts | Round whitish or yellowish structures that shine brightly (like “stars in the sky”) under nonpolarized dermoscopy | Intraepidermal keratin-filled cysts | |
| Further subclassified as small and starry, and as large and cloudy A9 | |||
| Comedo-like openings | Blackhead-like plugs on the surface of the lesion | Concave invaginations in the surface of the epidermis filled with keratin; some of these invaginations may correspond to follicular openings filled with keratin | |
| Fingerprint-like structures | Delicate, thin, light brown parallel running lines that do not interconnect to form a grid | Epidermal ridges | |
| Gyri and sulci | Gyri (ridges or fat fingers) and sulci (fissures) that create a cerebriform surface | Epidermal ridges with or without keratin filling the invaginations | |
| These invaginations can be filled with keratin, creating crypts | |||
| Moth-eaten borders | Concave invaginations of the lesion border | — | |
| Pigment network–like structure | Grid-like pattern that can resemble the pigment network seen in a melanocytic neoplasm | Ridges, crypts, and comedo-like openings distributed in a manner that gives the appearance of a grid | |
| Correspond to interconnecting epidermal ridges on the skin; the holes correspond to comedones or crypts | |||
| Lines tend to appear broader compared with the pigment network seen in nevi | |||
| Leaf-like structures | Brown to gray-blue discrete bulbous structures that may coalesce to create a shape that resembles a leaf | Large pigmented basal cell carcinoma tumor nests in the upper dermis | |
| Spoke wheel–like/concentric structures | Well-circumscribed brown to gray-blue-brown radial projections meeting at a darker brown central hub | Basal cell carcinoma tumor nests radiating from the dermoepidermal junction | |
| Large blue-gray ovoid nests | Large, well-circumscribed ovoid areas; larger than globules | Large basal cell carcinoma tumor nests in the dermis | |
| Blue-gray globules or dots | Multiple, nonaggregated, round, well-circumscribed structures | Small basal cell carcinoma tumor nests in the dermis | |
| Lacunae | Red (hemangioma), maroon (hemangioma and angiokeratoma), or black (angiokeratoma) lagoons often separated by septae | Dilated vascular spaces |
| Dermoscopic structures | Schematic illustration | Definition (morphology) | Diagnostic associations |
|---|---|---|---|
| Glomerular vessels | Coiled vessels mimicking the glomerular apparatus of the kidney | Bowenoid actinic keratosis, Bowen disease/squamous cell carcinomaA11,A13 | |
| Clear cell acanthoma | |||
| Hairpin vessels | U-shaped vessels | Keratinizing tumors such as keratoacanthoma and seborrheic keratosisA7,A11,A14 | |
| Not infrequently, may be twisted on its axis | |||
| Background: white halo common in keratinocytic tumors | |||
| U-shaped vessels | Irritated seborrheic keratosis, melanoma, basal cell carcinomaA15 | ||
| Not infrequently, may be twisted on its axis | |||
| Background: pink halo or pink background common in irritated seborrheic keratosis, but can also be seen in cutaneous malignancies | |||
| Arborizing vessels | Vessels with large diameter, branching irregularly into fine capillaries | Basal cell carcinomaA11, A13 | |
| Can also be seen in cysts, furuncles, and other adnexal tumors | |||
| Crown vessels | Branching or nonbranching vessels radiating toward the center of the lesion but without crossing its center | Sebaceous hyperplasiaA11 | |
| Molluscum contagiosum | |||
| Often associated with white/yellowish popcorn-like globular structures | |||
| Dotted or glomerular vessels in “string of pearls” or serpiginous distribution | Vessels distributed in a serpiginous pattern | Clear cell acanthoma | |
| Strawberry pattern | White-yellow follicular openings surrounded by a white halo, over a red background | Actinic keratosisA16 |
| Dermoscopic structures | Schematic illustration | Definition (morphology) | Diagnostic associations |
|---|---|---|---|
| Comma-shaped vessels | Slightly curved vessels | Dermal nevi, congenital melanocytic neviA11 | |
| Dotted vessels | Red dots (0.01 to 0.02 mm) | Spitz nevi, early melanoma (dotted over milky-red background)A11 | |
| Clark nevi (dotted over tan background) | |||
| Serpentine vessels | Irregular linear/undulating short vessels | Melanoma, congenital neviA11 | |
| Milky-red globules/vascular blush | Ill-defined globules of milky-red color and ill-defined areas of milky-red color | Amelanotic melanomaA11 | |
| Polymorphous vessels | Combination of two or more vessel morphologies | MelanomaA14 | |
| Most common combination is dotted and serpentine vessels | |||
| Corkscrew vessels | Coiled and tortuous vessels | Cutaneous melanoma metastases, nodular melanoma, desmoplastic melanoma |
