Bowen's disease is a precancerous form of SCC sometimes referred to as squamous cell carcinoma in situ. It develops slowly and is easily treated. The main sign is a red, scaly patch on the skin that may itch. It most commonly affects elderly women and is often found on the lower leg.
Noelle and Cali aren't the only twins to have played one child character in Friends. Double vision: Ross' cheeky son Ben (pictured), from his first marriage to Carol, was also played by twins, Dylan and Cole Sprouse, who are now 22.
In a statement to PEOPLE, Gellar reflects on Williams, who died of suicide Monday at the age of 63, and the indelible mark he made on her and her family. Gellar played the straightlaced daughter Sydney to Williams' eccentric ad man Simon in the CBS comedy that was cancelled in May after only one season.