Lentigo maligna commonly looks like a freckle, age spot, sun spot or brown patch that slowly changes shape and grows in size. The spot may be large in size, irregularly shaped with a smooth surface, and of multiple shades of brown and sometimes other colours.
Thickening of part of the lesion, increasing number of colours, ulceration or bleeding can be markers that the lesion is changing into a lentigo maligna melanoma.