<unk>  is the most common benign<unk> in tumor. Incidence increases with age. There is less prevalence in people with darker<unk> in. In large-cohort studies, 100% of the patients over age 50 had at least one<unk> . Onset is usually in middle age, although they are common in younger patients too—found in 12% of 15-year-olds to 25-year-olds—making the term "senile keratosis" a misnomer.
Seborrheic keratosis
Basal-cell carcinoma
Hydrocarbon keratosis
Melanoma
Arsenical keratosis
Wart
Actinic keratosis
Reactional keratosis