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. However, these lesions can also be found on skin that has not been exposed to the sun.Recent insights in the biology of seborrheic keratosis have been provided by the identification of somatic mutations in FGFR3, a growth factor receptor, in the cells composing the lesion.
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 melanoma.The average age of patients suffering from lesions with and without associated malignancy was 57 and 54 years,the approximate rate is highest with a prevalence of around 50% and the rate is estimated to be between 41% and 52% .
The cause of seborrhoeic keratoses is not known. The name is misleading, because they are not limited to a seborrhoeic distribution scalp, mid-face, chest, and upper back seborrhoeic keratoses are the most common benign tumor in older individuals. Seborrheic keratoses have a variety of clinical appearances, as seen in the images below, and they develop from the proliferation of epidermal cells.