View these YouTube videos on the different types of lines. Click on the arrow and when it starts go to the bottom of the screen and change the 360 resolution to 1080 and then click on the box with the arrows pointing out to enlarge to full screen. These videos are recorded in high definition. Press ESC on your keyboard to return to normal size.
Lines take precedence over other structures and lines reticular is a common structure because we look at a lot of nevi. Remember it is made up of the arrangement of pigmented cells over the dermal papillae (clear holes) and along the sides of the rete ridges (pigmented network).
Lines radial peripheral represent confluent junctional nests of melanocytes that are rapidly proliferating, They are a feature of Spitz and Reed nevi but when asymmetrically distributed around a pigmented lesion then you should consider melanoma.
Pseudopods are lines radial peripheral with a knob joined to the streak at the end. They are also seen in Spitz, Reed nevi and melanoma. If asymmetrically distributed then consider melanoma and biopsy remove.
View this YouTube video on Lines Parallel
White Lines
White lines are seen in mainly BCCs, invasive melanomas and in Dermatofibromas and scars and some Spitz nevi. They are best seen with a polarising dermatoscope. They may cross each other at right angles. Some people believe these white lines are just polarising artefacts but I doubt it. Collagen in the dermis is birefringent to polarised light. Sometimes these white lines on a pink background are all you see in a desmoplastic melanoma!