Seborrheic keratosis is the most common benign skin tumor with increasing indidence in elderly individuals and no predilection of genre. There is less prevalence in people with darker skin.According to large-cohort studies, 100% of the over-50-year-old patients harbored at least one seborrhoeic keratosis.
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 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.
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 a growth factor receptor, in the cells composing the lesion.