Surgical margins of excision for basal cell carcinoma and squamous cell carcinoma.

In excising basal and squamous cell carcinomata, the surgical margin that is wide enough to completely remove the tumor an acceptable percentage of the time and narrow enough to minimize removal of excessive normal tissue must be selected. This task can be reliably accomplished with comprehensive knowledge of factors that affect subclinical tumor extension such as tumor appearance, diameter, histology, location, treatment status, and, in the case of squamous cell carcinoma, vertical invasion depth and involvement of subcutaneous fat. Information regarding these factors along with specific recommendations about excisional margins for basal cell and squamous cell carcinomata is presented.