Step by step procedure

Mohs surgery is performed as an outpatient procedure in the physician’s office. Office based procedures help to keep the medical cost at a minimum and the safety at a maximum. Only local numbing medicine is required (no general anesthesia).

Although the patient is awake during the entire procedure, discomfort is usually minimal and no greater than it would be for more routine skin cancer surgeries or your initial biopsy.


We encourge you to reach out to us with any questions or concerns you might have about a particular condition and the proper treatments. Come in or give us a call to set up a consultation to discuss the treatment process.

step 1

The area to be treated is cleansed, marked, and injected with a local anesthetic. The Mohs surgeon removes the visible cancer, along with a thin layer of surrounding tissue. Following this procedure the patient may return to the waiting room while tissue is being processed and examined by Dr. Allen. Dermatology Specialists of Boulder houses an on-site, state-of-the-art CLIA certified lab to evaluate tissue specimens safely, rapidly and effectively

step 2

The removed tissue specimen is cut into sections, stained, and marked on a detailed diagram. A reference map is created.

step 3

Tissue is frozen on a cryostat, and the technician removes very thin slices from the entire edge and under-surface. These slices are then placed on slides and stained for examination under the microscope. (This is the most time-consuming portion of the procedure. During this time, you may be bandaged and in the Mohs waiting room with coffee, tea, snacks available to you while you wait.)

step 4

The Mohs surgeon carefully examines the entire under-surface and complete edges of the specimen, and all microscopic roots of the cancer are precisely identified and pinpointed on the Mohs map. Upon microscopic examination, if residual cancer is found, the Mohs surgeon utilizes the Mohs map to direct the removal of additional skin cancer. (Note that additional tissue is removed only where cancer is present.)

step 5

This process is repeated as many times as necessary to locate and remove any remaining cancerous roots.

step 6

When microscopic examination reveals that there is no remaining tumor, the surgical area is ready to repair.