Pigment network

From dermoscopedia

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 Editor: Ralph P. Braun

 Author(s): Ralph P. Braun     ·  Katrin Kerl
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Description In this cover we describe the 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. criterion pigment networkThis glossary term has not yet been described. and its variants such as pseudonetworkA structureless pigment area interrupted by non-pigmented adnexal openings, atypical pigment networkNetwork with increased variability in the color, thickness, and spacing of the lines of the network; asymmetrically distributed; gray color and typical pigment networkNetwork with minimal variability in the color, thickness, and spacing of the lines; symmetrically distributed delicate network light brown, thin network lines and its histologic correlation
Author(s) Ralph P. Braun · Katrin Kerl
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Status update July 24, 2018
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Pigment NetworkThis glossary term has not yet been described.

The pigment network consists of a grid of intersecting pigmented “linesstreaksThis glossary term has not yet been described.” forming a honeycomb pattern [1]. 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 [2]. 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 network 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, ink spot lentigo or accessory nipples [3].

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 network 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 [4]. 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. [1] .

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 pseudonetwork 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


ReferencesThis is material contained in a footnote or bibliography holding further information.
  1. 1.01.1 Kittler et al.: Standardization of terminology in dermoscopy/dermatoscopyThe 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.: Results of the third consensus conference of the International Society of 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.. J. Am. Acad. Dermatol. 2016;74:1093-106. PMID: 26896294. DOI.
  2. Massi et al.: Histopathologic correlates of dermoscopic criteriameasure of how well one variable or set of variables predicts an outcome. Dermatol Clin 2001;19:259-68, vii. PMID: 11556235.
  3. Scope et al.: NonmelanocyticThis glossary term has not yet been described. lesions defying the two-step dermoscopy algorithmIn mathematics and computer science, an algorithm (Listeni/ˈælɡərɪðəm/ AL-gə-ri-dhəm) is a self-contained sequence of actions to be performed. Algorithms can perform calculation, data processing and automated reasoning tasks.. Dermatol Surg 2006;32:1398-406. PMID: 17083595. DOI.
  4. Russo et al.: Dermoscopy pathologyThis glossary term has not yet been described. correlation in melanoma. J. Dermatol. 2017;44:507-514. PMID: 28447355. DOI.