Treatment Reference

After the wafer is cut into pieces and its edges color-coded with dyes, a map is drawn so that the surgeon can mark areas of tumor seen when the sections are examined microscopically. The surgeon may then return to the patient and know the specific location of any remaining tumor.

To cut the sections for microscopic examination, the specimen is flattened and frozen sections are performed on the undersurface of each section. The Mohs surgeon then reads each frozen-section specimen and marks any tumor that is found on the corresponding area of the map. Any remaining tumor that is present is removed by excising another thin layer of skin from the area of the wound that corresponds to the marked area on the map. During the processing and reading of the slides, the patient may wait in the waiting room. The processing is accomplished rapidly in order to prevent loss of anesthesia, thereby minimizing the discomfort of further anesthetic injections.

For primary basal-cell carcinomas, the cure rate using Mohs surgery is close to 99 percent, which is higher than any other treatment method available. Cure rates for recurrent basal-cell carcinomas are greater than 96% percent with Mohs surgery, compared to an approximate 50 percent cure rate when conventional surgical excision is used to guess the clinical margins of recurrent tumors. The reason for these high cure rates is that Mohs surgery allows for the complete examination of the surgical margins.

Mohs surgery has the ability to conserve normal tissue. Conservation of a maximal amount of normal tissue allows for the best possible reconstructive repair procedure. Well-trained Mohs surgeons are adept at performing reconstructive surgery, including flaps, grafts, and primary closures. In addition, because only a minimal amount of normal tissue is sacrificed, some excisions result in only partial thickness wounds, which allows for the best possible cosmetic result by the simple management of healing by granulation and epithelialization. Scar revision at a later date is still possible if the scar is unacceptable to the patient. Approximately 50 percent of surgical defects are managed by immediate postoperative reconstruction.

Mohs micrographic surgery is more expensive than curettage-desiccation, cryosurgery, or simple excisional surgery. These other methods of tumor destruction are still cost-effective in the treatment of primary tumors in areas where tumors have a tendency not to recur and where wide surgical margins would not compromise the cosmetic results.