Mohs surgery is a specialized, highly effective technique for removing skin cancers. It was developed in the 1930s by Dr. Frederick Mohs at the University of Wisconsin and is now practiced throughout the world. Mohs surgery differs from other skin cancer treatments in that it permits the immediate and complete microscopic examination of the removed cancer tissue so that all roots and extensions of cancer can be eliminated. Mohs surgery has the highest reported cure rate of all treatments for skin cancer. Treating all skin cancers with Mohs surgery is not necessary. Mohs surgery is reserved for skin cancers that grow back after previous treatment, cancers that are at high risk of reoccurring, or cancers that are located in cosmetic areas where preservation of the maximum amount of normal skin is important.