Mohs surgery, also known as "Chemosurgery", was created by a general surgeon, Dr. Fredrick E. Mohs, is microscopically controlled surgery that is highly effective for common types of skin cancer, with a cure rate cited between 97% and 99% for primary basal cell carcinoma, the most common type of skin cancer, and for squamous cell carcinoma. Recurrent basal cell cancer has a lower cure rate with Mohs surgery, more in the range of 94% It has been used in the removal of melanoma-in-situ (cure rate 77%), and certain types of melanoma (cure rate 52%). Other indications for Mohs surgery include dermatofibrosarcoma protuberans, keratoacanthoma' spindle cell tumors, sebaceous carcinomas, microcystic adnexal carcinoma, merkel cell carcinoma, Pagets's disease of the breast, atypical fibroxanthoma, leimyosarcoma, and angiosarcoma. Because the Mohs procedure is micrographically controlled, it provides precise removal of the cancerous tissue, while healthy tissue is spared. Mohs surgery is relatively expensive when compared to other surgical modalities. However, in anatomically important areas (eyelid, nose, lips), tissue sparing and low recurrence rate makes it a procedure of choice by many physicians.

From http://en.wikipedia.org/wiki/Mohs_surgery