Dermoscopic features of basal cell carcinomas: differences in appearance under non-polarized and polarized light

Background: Basal cell carcinomas (BCCs) can be diagnosed using different dermoscopic modalities.

Objective: To evaluate dermoscopic features of BCCs using nonpolarized and polarized dermoscopy to highlight similarities and differences between dermoscopic modalities.

Materials and methods: Retrospective study of 149 BCCs under nonpolarized dermoscopy (NPD), polarized contact dermoscopy (PCD), and polarized noncontact dermoscopy (PNCD). Images were evaluated for a range of dermoscopic colors, structures, and vessels. Features were compared according to histopathologic subtype.

Results: The most common dermoscopic structures in BCCs across all modalities included globules (50.3-51.0%), dots (49.7-50.3%), white structureless areas (63.1-74.5%), structureless gray-brown areas (24.2-24.8%), and ulcerations (28.2%). The most frequently observed vasculature included arborizing vessels (18.8-38.3%), short fine telangiectasias (SFTs) (73.8-82.6%), and vascular blush (41.6-83.2%). Structures with higher levels of agreement across modalities included pigmented structures and ulcerations. Lower levels of agreement existed between contact and noncontact modalities for certain vascular features. White shiny structures, which include shiny white lines (chrysalis and crystalline structures) (0-69.1%), shiny white areas (0-25.5%), and rosettes (0-11.4%), exhibited no agreement between NPD and polarized modalities.

Conclusions: This study highlights differences in dermoscopic features of BCCs under three dermoscopic modalities. Shiny white lines (chrysalis and crystalline structures) and shiny white areas may be used as additional criteria to diagnose BCCs.