Seborrheic keratosis

A seborrheic keratosis is a benign skin growth that is very common among people over 40 years of age.

Presentation
The growths resemble flattened or raised warts, but have no viral origins and may exhibit a variety of colors, from pink or yellow through brown and black. Because only the top layers of the epidermis are involved, seborrheic keratoses are often described as having a "pasted-on" appearance.

Treatment
Because the tumors are rarely painful, treatment is not often necessary. There is a small risk of localized infection caused by picking at the lesion. If a growth becomes excessively itchy, or if it is irritated by clothing or jewelry, cryosurgery has been found to be highly effective in their removal. The main danger associated with seborrheic keratoses lies in their resemblance to malignant melanomas, which has sometimes led to a misdiagnosis of the cancerous lesions. If there is any doubt, a skin biopsy will allow a physician to make a correct diagnosis.

Causes
A mutation of a gene coding for a growth factor receptor (FGFR3), has been associated with seborrheic keratosis.