SAN DIEGO Neophyte Mohs surgeons should start with an easy case, ideally with a lesion located anywhere other than on the face, and, if possible, give the case an entire day on the schedule.
That was just one bit of advice given by Dr. Howard K. Steinman at a meeting sponsored by the American Society for Mohs Surgery.
Another tip provided by Dr. Steinman, one of the meeting's organizers, was that one should photograph the lesion on the day one first sees the patient, at the time of the evaluation.
Sometimes, a lesion readily apparent on the day of the evaluation is not so obvious on the day of surgery, and to illustrate his point, Dr. Steinman showed a picture of a biopsy-confirmed lesion that had almost completely disappeared when the patient showed up for surgery. It would have been difficult to find that lesion again if not for the picture, Dr. Steinman noted.
Some surgeons curette a lesion before taking the first Mohs stage, and some surgeons do not, Dr. Steinman pointed out, but he said it can be helpful in planning the procedure, particularly because it can give the surgeon a better idea of tumor depth.
In Mohs, when the surgeon takes the first stage, the blade should be angled at 45 degrees, not so much so the lesion can be removed easily as so it will lay flat when being sectioned. And, the stage should be taken at a depth one tissue layer below the expected margin of the lesion.
The key to removing the lesion is marking it with reference marks before it is removed from the patient and with the different colors appropriately after it is removed.
Otherwise, it is too easy for the specimen to fall to the floor, or be turned inadvertently, or even flipped while being sliced in the cryostat, with the result that the surgeon becomes uncertain where the proper margin is, explained Dr. Steinman, who practices in Chula Vista, Calif.
The making of the reference marks around the lesion to be removed is, of course, up to the surgeon but a common practice is to use five, one at what is decided will be the 12 o'clock mark on the specimen, and one each at 9, 6, and 3 o'clock. The fifth mark goes immediately next to the 12 o'clock reference mark, usually, so that mark can be distinguished, he added.
Reasons for a second stage, in the absence of tumor that clearly crosses the edge of the section, include a hole in the section, misorientation because the section is not clearly marked, and/or dense inflammation at the edge of the section, which can indicate tumor, Dr. Steinman said.