These growths often appear in middle-aged and older adults. Some people get just one. It is, however, more common to have many. They are not contagious. Most often seborrheic keratoses start as small, rough bumps. Seborrheic keratosis is a common skin growth. It may look worrisome, but it is benign not cancer .Then slowly they thicken and get a warty surface. They range in color from white to black. Most are tan or brown.
The etiology of seborrheic keratosis is poorly understood.It has been hypothesized that, since seborrheic keratosis often occurs on sun-exposed areas, ultraviolet light might be involved in their pathogenesis around 50% and the rate is estimated to be between 16% and 34% Seborrheic keratoseson exposed areas were more often flat and more than 3 mm in diameter than those on the non-exposed areas.
Furthermore, thin seborrheic keratoses on facial skin can be very difficult to differentiate from lentigomaligna even with dermatoscopy.Visual diagnosis is made by the stuck on appearance, horny pearls or cysts embedded in the structure. Darkly pigmented lesions can be challenging to distinguish from nodular melanomas.