Seborrheic keratoses (SK) are non-cancerous skin growths that usually appear in older individuals, but can also affect younger adults. They are typically slow-growing and develop their texture gradually over time, although they can vary widely in appearance and size. While SKs usually grow slowly, if many SKs erupt suddenly together, it might raise some concern. This unusual occurrence has sometimes been considered a sign of internal cancer, and doctors call it “the sign of Leser Trélat”. The size of SK growths can also vary dramatically from small pinpoint dots to large spots the size of a quarter or even bigger. Most SKs begin as skin that suddenly feels waxy or bumpy in texture. This area may thicken, forming tough growths that look like warts or moles. In some cases SKs can grow up to 8 to 10 millimeters larger than they should be and develop deep pits and cracks over time. However, the growth rate of SKs may vary significantly among individuals, and more research is needed to determine the exact growth rate of these skin lesions.