Shiny white lines

Dermoscopic Description
Shiny white lines are whiter than the surrounding skin, and only visible with polarised light. They are due to different structures on raised parts of lesions compared with flat parts.

What the structures correspond to histologically
Shiny white lines in flat parts of lesions correspond to hyaline fibrous bands of collagen or fibrosis/fibroplasia of the papillary dermis. In raised parts of a lesion, shiny white lines correspond to areas of hypergranulosis.

Lesions in which the structures arise
In melanocytic lesions, they should raise suspicion for melanoma. They are also found in many other lesions such as dermatofibromas, spitz naevi, actinic keratoses, angiomas, pyogenic granulomas and adnexal tumours.