How Long Does It Take to Remove 5 Layers in the Moh's Procedure

It takes about 1-2 minutes to harvest each layer of skin.  The time between layers, however, is highly variable.  This is dependent on how long the technician takes to prepare the slide.  In my practice, this can take anywhere from 5 – 30 minutes.  Therefore, it would be approximately 35 minutes to 2 hours and 40 minutes total time for five layers.  After the cancer has been cleared it takes another 10-30 minutes to surgically close the wound.

Mohs surgery is a highly specialized in-office procedure for treating skin cancer. The procedure involves removing a tumor, layer-by-layer, down to its root, while sparing the surrounding healthy tissue. Every time a layer of skin tissue is taken, the tissue is processed in an onsite lab and examined under a microscope. Therefore, the Mohs procedure really has 2 steps: the surgery itself, and the processing in the lab.

The surgery is quite quick. It usually takes about 5 minute to remove a layer of skin tissue. The lab processing, however, usually takes a longer duration of time. Depending on the clinic, this could take 30-60 minutes per layer of tissue. The number of layers required is variable, and really depends on the roots and growth pattern of your cancer. One average, 1-2 layers are required. Because the time involved in the procedure is somewhat unpredictable, I often tell patients to block a half day, wear comfortable clothing, bring a book, laptop, spouse or friend to help pass the time.

Mohs Surgery, named after the inventor, Frederick Mohs, is where the surgeon also acts as the pathologist and runs a lab where the entire margin is checked for any remaining skin cancer. This is different than a frozen section at most hospitals, where only partial samples are checked, and thus remaining skin cancer can be missed when the cancer has an irregular shape or growth pattern.

In our office each layer or stage normally takes 30-45 minutes to excise and check in the lab. The average patient requires two stages, so the entire procedure, including sewing up at the end, takes about an hour and a half to two hours.

The stages and wait times in our office are this short because the procedure is such a high priority for us. Everything has been prepared in advance of the patient's arrival. As soon as the tissue is removed it is transported down the hall where it is immediately mapped, sliced onto slides, stained, and then looked at under the microscope.

While the patient is waiting, a temporary bandage is worn, and the person can lie or sit up in a chair. A friend or family member is welcome to accompany the patient and thus helps to pass the time while waiting for the "all clear" report.

When you see the doctor that will perform your Mohs Surgery, you will be told or you can ask how long the doctor thinks the procedure might take.

Don't worry, even if it takes several stages, more numbing medicine can be used so that the anesthetic never "wears off."