Shiny white streaks in a thin melanoma
These structures are due to collagen in the dermis and are described as orthogonal white structures at right angles to each other. Said to be much more readily seen on cross polarising (no touch ) dermoscopy, although I find I do see them to some extent on the glass plate liquid contact dermoscope I use most of the time. They have been called chrysalis or crystalline structures. Shiny white streaks (SWS) seems a better name and I will adopt it henceforth.
It is said to be associated with melanoma and may be the only dermoscopic sign in a featureless melanoma so although you won’t see it very often, when you do see it SWS may be crucial. These pesky non pigmented melanomas can be hard to diagnose so if anything can help us, we should take it with both hands.. This is a fairly obvious melanoma to the unaided eye with irregular shape, outline and colour. Dermoscopy amplifies these features. This is a chaotic lesion with multiple colours and patterns, irregular dots and globules at 2 o’clock and eccentric black blotches forming up in the bottom right quadrant.
Additionally, to right of centre some shiny white streaks are seen. Click on the image to magnify. These are ‘icing on the cake’ as far as this diagnosis is concerned, but sometimes in a less pigmented melanoma they might be the only positive feature on offer to the dermoscopist, give or take some polymorphous vessels.
Shiny white streaks: the more sensible name for the chrysalis sign/crystalline structures. Seen in some melanomas, basal cell cancers, squamous cell cancers and dermatofibromas. If a positive diagnosis of dermatofibroma can be confidently made, I wouldn’t worry. Otherwise, referral or excision without delay.