On the Definition of Mohs Surgery and How It Determines Appropriate Surgical Margins

Abstract

Mohs surgery (also called chemosurgery, microscopically controlled excision, histographic surgery, and Mohs micrographic surgery) is widely used for excising difficult malignancies of the skin. The procedure is well known and has been described in detail in many reviews.^1-3It is most commonly used for basal cell carcinomas (BCCs) or squamous cell carcinomas, but it has also been used for melanomas,^4,5other malignancies,^3,6and even gangrene.^1,6The best indications, roughly in order of importance, are persistent (recurrent) tumors, poorly defined margins, aggressive histologic types (sclerosing, basosquamous), high-risk anatomic sites or those with high functional or aesthetic value (ears, nose, eyelids), large neoplasms, or incompletely excised neoplasms. None of these indications are absolute, as alternative modalities for treatment exist.^7,8" About 5% of Mohs surgeons believe that all BCCs require Mohs surgery," but most would agree that this is an excessive use of resources, despite the extremely high cure rates obtained with the technique. It is difficult to precisely define the term Mohs surgery. Medical terminology and definitions continually evolve over the years to the point that sometimes a term becomes so modified as to have an uncertain meaning. Different authors often use the same term when, in fact, they are writing about different things