Basal-cell Carcinoma - Treatment - Standard Surgical Excision

Standard Surgical Excision

This can be with either frozen section histology, or paraffin-embedded fixed-tissue pathology. It is the preferred method for removal of most BCCs. A dermatoscope can help an experienced surgeon accurately identify the visible tumour that the naked eye can not see.

The cure rate for this method, whether performed by an otolaryngologist-head & neck surgeon, plastic surgeon, or dermatologist is totally dependent on the surgical margin. The narrower the free surgical margin (skin removed that is free of visible tumor) the higher the recurrence rate. If a 4 mm free surgical margin is obtained around a small tumor (less than 6mm), or a wider 6 mm free surgical margin is obtained around a larger tumor (greater than 6mm), the cure rate is very high - 95% or better. However, for cosmetic reasons, many doctors take only very small surgical margins 1–2 mm, especially when operating on the face. In such a case, a pathology report indicating the margins are free of residual tumour is often inaccurate, and a recurrence rates are much higher (up to 38%).

A weakness with standard surgical excision is the high recurrence rate of basal-cell cancers of the face, especially around eyelids, nose, and facial structures. A diagram on page 33 of the NCCN publication demonstrate the area of high risk of recurrence as most the face with the exception of the central cheek and upper forehead. On the face, or on recurrent basal-cell cancer after previous surgery, special surgical margin controlled processing (CCPDMA - complete circumferential peripheral and deep margin assessment) using frozen section histology (Mohs surgery is one of the methods) is required.

With surgical margin controlled frozen section histology, a surgeon can achieve a high cure rate and low recurrence rate on the same day of the excision. However, most standard excisions done in a plastic surgeon or dermatologist's office are sent to an outside laboratory for standard bread loafing method of processing. With this method, it is likely that less than 5% of the surgical margin is examined, as each slice of tissue is only 6 micrometres thick, about 3 to 4 serial slices are obtained per section, and only about 3 to 4 sections are obtained per specimen (see figure 2 of reference).

When in doubt, a patient should demand that either Mohs surgery or frozen section histology with either margin control (ccpdma) or thin serial bread-loafing is utilized when dealing with a tumour on the face. The pathologist processing the frozen section specimen should cut multiple sections through the block to minimize the false negative error rate. Or one should simply process the tissue utilizing a method approximating the Mohs method (described in most basic histopathology text books or described in this reference ) during frozen section processing. Unfortunately, these methods are difficult when applied to frozen sections; and is very tedious to process. When not utilizing frozen section, the surgeon might have to wait a week or more, before informing the patient if more tumour is left, or if the surgical margin is too narrow. And a second surgery must be performed to remove the residual or potential residual tumour once the surgeon inform the patient of the positive or narrow surgical margin on the surgical pathology report.