Mohs micrographic surgery achieves the highest documented cure rates for the skin cancers where it’s indicated while removing the least amount of healthy tissue — two goals that usually trade against each other in surgery, resolved here through a methodological innovation rather than a compromise.
The procedure was developed by Dr. Frederic Mohs in the 1930s and refined significantly over subsequent decades. Today it is the standard of care for basal cell and squamous cell carcinomas in high-risk locations, recurrent tumors, and cases with aggressive histological features. Dr. Herbst completed fellowship training specifically in Mohs surgery — a credential that signifies advanced, specialized training beyond standard dermatologic residency.
Why Mohs is different
In standard excisional surgery, the surgeon removes the tumor with a planned margin, the specimen goes to an outside pathology lab, and results return days later. The pathologic sampling in standard excision typically examines only a portion of the total margin. Mohs keeps the surgeon and the pathologist as the same person. After each tissue layer is removed, it is mapped, processed, and examined under the microscope in our office — on the same day, while the patient waits. The surgeon examines 100 percent of the surgical margin. If any cancer remains, its precise location is identified on the tissue map, and only that specific area is removed in the next stage.
The result: cure rates above 99 percent for primary basal cell carcinoma and 97 percent or higher for recurrent tumors — figures consistently higher than other treatment approaches — with the smallest possible amount of healthy tissue removed.
When Mohs is the right choice
Mohs is most often recommended for skin cancers in cosmetically or functionally important areas — the face, particularly around the eyes, nose, lips, and ears; the scalp; the hands and feet. In these locations, every millimeter of preserved healthy tissue matters.
Mohs is also appropriate for tumors that are large, have indistinct clinical borders, have recurred after prior treatment, occur in patients who are immunocompromised, or have histological features suggesting aggressive behavior — such as perineural invasion or morpheaform (sclerosing) growth pattern. It is not indicated for every skin cancer. We discuss each case individually and explain our recommendation, including the reasoning behind it.
What the day of surgery looks like
Mohs surgery is performed in our office under local anesthesia. Plan for a full day. Not because the surgery itself is lengthy, but because tissue processing between stages takes time — typically one to two hours per stage. Most procedures involve one to three stages. There is no way to predict reliably in advance how many will be needed for a given case.
While tissue is being processed, you wait in the office. Patients often bring reading material or a companion. We keep you informed throughout. Once the final stage confirms clear margins, we move immediately to wound closure. The reconstruction plan is discussed at this point, when we know the exact size and location of what needs to be repaired. Options include layered primary closure, a local skin flap using adjacent tissue, a skin graft, or in appropriate cases, allowing the wound to heal by secondary intention.
Frequently asked questions
Is Mohs surgery painful?
The procedure is performed under local anesthesia throughout. Most patients are surprised by how manageable the experience is. The initial injection to numb the area produces a brief sting; after that, the surgical stages are typically well-tolerated. Some soreness, swelling, and bruising in the days following surgery are normal.
How long will I be in the office?
Plan for a full day. Some straightforward cases clear in one stage by midmorning. Others take longer. We know this is disruptive and try to move efficiently without sacrificing the quality of what we’re doing.
What will the scar look like?
Mohs surgery preserves as much healthy tissue as possible, which generally produces better cosmetic outcomes than less precise approaches. Some scarring is inevitable. Scars look their worst at three to six months and improve substantially over the following year as the tissue remodels. We provide specific scar care guidance and follow up to monitor healing.
Is reconstruction done the same day?
In most cases, yes. Reconstruction is planned and performed on the day of Mohs, once clear margins are confirmed. Occasionally, for complex reconstructions or when a plastic surgery referral would better serve the patient, it may be staged separately. We discuss this with you before the procedure.
Who is a candidate for Mohs?
The clearest candidates are patients with basal cell or squamous cell carcinoma in a high-risk location, recurrent tumors, or tumors with aggressive features. Patients who are immunocompromised often warrant Mohs even for otherwise lower-risk cancers. We evaluate each case individually.