What is Mohs surgery?

In 1936, Dr. Frederic Mohs, of the University of Wisconsin, developed a precise tumor extirpation technique that involved the controlled, serial, microscopic examination of tissue that had been chemically fixed with zinc chloride paste. The excised tissue was systematically mapped, frozen sections were examined, and the process was then repeated at foci of residual malignancy until a completely tumor-free plane was reached. The goals of Mohs surgery are to completely remove the tumor and to maximize tissue conservation.