|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|
|Responsible author||Ralph Braun → send e-mail|
|Status update||July 24, 2018|
|Status by||Ralph P. Braun|
The pigment network 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:
Typical networkNetwork with minimal variability in the color thickness and spacing of the lines; symmetrically distributedcolorColor (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.
On histopathologyThis glossary term has not yet been described., the lines of the typical networkNetwork with minimal variability in the color thickness and spacing of the lines; symmetrically distributed correspond to pigment in rete ridgesEpidermal extensions that project into the underlying dermis. That are relatively uniform in width and equidistant from each other.
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 heavily pigmented rete ridges as encountered in dermatofibromas.
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”.
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 nests of melanocytes. 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..
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 nonglabrous skinThis glossary term has not yet been described.. Accordingly, the pigment network is usually absent in these locations and is replaced by a pseudonetwork pattern.