In a 50-year-old female patient a new changed and pigmented skin tumour (5x12mm) appeared on her right forehead in the last eight to ten months.
Low UV-exposure and no injury was reported.
She had skin type III, about 30 non suspicious nevi, no history of melanoma in her life or her family.

In dermoscopy an asymmetric tumour with sharp margins is visible. Some pseudohorncysts and multiple follicular openings are seen. The range of light brown to grey-bluish colours is presented. In the depigmented centre some komma-like vessels are detectable.

Dermoscopical diagnose
Seborrhoic keratosis

Remarks
The differential diagnosis of a lentigo-maligna or an early lentigo-maligna-melanoma must be considered.