A giant nevus
, commonly referred to as the giant congenital nevus
, is a very rare form of nevus, generally called a mole but of a much larger size than a normal specimen. A nevus is defined as giant if it has a diameter of over 20 centimeters, and in the most extreme cases, it can cover practically the entire surface of the skin. This type of nevus is present at birth
, hence its categorization as a congenital nevus. It is usually accompanied by smaller nevi on the rest of the skin, and in order to avoid psychological insecurities and limit risks of it evolving into a skin cancer
, which are higher with this type of nevus, ablation is often discussed on a case by case basis.