- 1 Reticular lines
- 2 Branched lines
- 3 Angulated lines
- 4 Parallel lines
- 5 Radial lines
- 6 Curved lines
Lines may form six different patternsThis glossary term has not yet been described., depending on their shape and arrangementThis glossary term has not yet been described.: reticular, branched, angulated, parallel, radial, and curved.reticular linespigment network melanocytic lesions dermatofibroma solar lentigo are not always melanocyticThis glossary term has not yet been described.. In most cases the histological correlate of reticular lines is hyperpigmentation of basal keratinocytes, which may or may not be created by an increase in the numbers of melanocytes.
- Usually light-brown or dark-brown, due to melanin in the epidermis.
- If the pigment is very dense, the lines are black.
- Rarely, they can appear gray.
Not every shade of brown is to be interpreted as a separate 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.. One or two black lines do not render the lesion multicolored. The normal hypopigmentation around follicular openings does not create an extra color. Nearly all pigmented lesions are somewhat lighter at the periphery than in the center.
Light-brown + thin reticular lines:
are usually seen in junctional Clark nevus or solar lentigoThis glossary term has not yet been described.
A Clark nevus is round or oval and the pigmentation does not end abruptly at the periphery. The border of a solar lentigo is usually sharply demarcated and scalloped.
Differential diagnoses: a variant of 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. with reticular lines only and urticaria pigmentosa, a type of mastocytosisThis glossary term has not yet been described..
Brown reticular lines + thick:Solar lentigoThis glossary term has not yet been described., seborrheic keratosisThis glossary term has not yet been described..
Black (very dark-brown) reticular lines:
More than one color + reticular lines:
solar lentigo or seborrheic keratosis
- CluesEvidence, in an investigation to solar lentigo: well-demarcated, scalloped border.
- Clues to seborrheic keratosis: white dots or clodsThis glossary term has not yet been described., orange or yellow clods, well-demarcated border, circlesThis glossary term has not yet been described., thick curved lines, vesselsThis glossary term has not yet been described. as loops or coils.
- Differential diagnoses: Clark nevus, "superficial" or "superficial and deep" congenital nevus, and in situThis glossary term has not yet been described. melanomaThis glossary term has not yet been described.
Dark-brown or black and light-brown areas:
variegate color distribution
- Differential diagnosis: Clark nevus, "superficial" or "superficial and deep" congenital nevus, or in situ melanoma
- Only 5 of the 8 clues to melanoma are seen in reticular pattern lesions:
- gray 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)., clods, circles or lines;
- radial lines or pseudopods seen only in some segments of the periphery;
- black dots or clods at the periphery
- thick reticular lines and e) angulated lines (polygonslines angulated or polygonal (non-facial skin)). When one of these clues is present, the diagnosis of melanoma should be seriously considered.
- Eccentric hyperpigmentation ,i.e. the more heavily pigmented area is not in the center but the periphery: Clark neviThis glossary term has not yet been described. and in situ melanomas, rarely in 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..
Differential diagnosis: MelanomaThis glossary term has not yet been described.. When no clue to melanoma is present, a Clark nevus is the most likely diagnosis.
Branched lines and reticular lines are closely related and often occur together. Lesions that are exclusively composed of branched lines are either black or brown, and they are all benignis any condition that is harmless in the long run.
Brown branched lines:Clark nevus or "superficial" or "superficial and deep" congenital nevus
Black (or very dark-brown) branched lines:
Angulated linesSyn: polygons, zig-zag pattern Gray-brown lines that are connected at an angle or coalescing to form polygons
- They are the hallmark of flat melanomas on chronic sun-damaged skinThis glossary term has not yet been described..
- Most melanomas with angulated lines are not invasive (in situ).
- They are usually brown or grey.
- Typical pigment pattern of acralPertaining to peripheral body parts, especially hands, feet, fingers, and toes. skin.
- They may be arranged in one of three ways; on the ridges (ridgeThis glossary term has not yet been described. pattern), in the furrows (furrow pattern), or crossing ridges (crossing pattern).
- AcralPertaining to peripheral body parts, especially hands, feet, fingers, and toes. lesions that only show a pattern of furrows or a crossing pattern may be safely considered to be benign.
- Assessment of a lesion showing the ridge pattern proceeds by evaluating color.
- If it is brown, in situ melanoma must be considered. Black, red or purple parallel lines on the ridges indicate either hemorrhage or exogenous pigmentation. Satellite clods are a strong clue to the diagnosis of hemorrhage.