The tendency to develop seborrheic keratoses is inherited.
Seborrheic keratoses are harmless and almost never become malignant.
Seborrheic keratoses begin as slightly raised, light brown spots. Gradually they thicken and take on a rough, wartlike surface. They slowly darken and may turn black. These color changes are harmless.
Seborrheic keratoses are superficial and look as if they were stuck on the skin.