Dermoscopy is very useful for the early recognition of basal and squamous cell carcinoma.
For basal cell carcinoma, the presence of any disease-specific pigmented structure usually allows a specific diagnosis (leaf-like areas, spoke wheel areas, blue-gray ovoid nests, blue-gray globules).
Non-pigmented basal cell carcinoma is dermoscopically typified mainly by the presence of arborizing vessels. Although frequently present, the latter criterion is not highly specific, since similar vessels can be seen in other tumors.
The most useful dermoscopic clue for the diagnosis of intraepidermal squamous cell carcinoma is the presence of coiled (glomerular) vessels. Ideally, the vessels are arranged in clusters and are associated with white/yellowish scales. Pigmented BD might additionally display multiple brown dots distributed either in clusters or in a linear fashion at the periphery.
The predominant dermoscopic feature of well-differentiated invasive SCC is white color. The white color might correspond to keratin, white structureless areas, white circles (surrounding follicular openings), white halos (surrounding vessels) or a combination of these features. The most frequent morphologic type of vessels in well-differentiated SCC is hairpin vessels.
In contrast, poorly differentiated SCC is typified by a red predominant color, which is a result of either bleeding or an intense vascularity consisting of vessels of several morphologic types (linear, dotted, hairpin, linear irregular).
Basosquamous carcinoma is dermoscopically characterized by the presence of at least one BCC-associated criterion (ex. arborizing vessels or ovoid nests), plus at least one SCC-associated criterion (ex. white circles).