Mohs Micrographic Surgery



What is Mohs Surgery?

Mohs micrographic surgery was originally developed in the 1930s by Dr. Frederic Mohs at the University of Wisconsin. Mohs surgery is a precise surgical process in which a dermatologist performs the surgery and then examines the margins of the removed tissue immediately under a microscope to determine if any cancer remains. It works very well when small areas of extramammary Paget's disease (EMPD) are located.

Tissue samples taken during 'slow Mohs' surgeries are carefully labeled so that surgeons will know what areas of the patient may still have extramammary Paget's disease (EMPD).

For larger areas of EMPD, 'slow Mohs' is often used.

Slow Mohs (or staged excision) is a way of removing extramammary Paget's disease skin cancer in a precise way. Often this is done over a number of patient visits. During each procedure the Mohs surgeon removes tissue but instead of immediately examining the tissue in the surgical suite under a microscope, it is sent off to pathology. The Mohs surgeon marks the samples carefully as to be able to determine where the tissue originated on the patient. The patient is often bandaged and sent home until the pathology review is completed.

Slow Mohs surgery requires careful communication between the surgeon and the pathology laboratory to insure that specimens and pathology results are correlated. 

When the results of the pathology are returned, and all the edges are determined to be free of cancer, the Mohs surgeon may close the site or refer the patient to another physician. Slow Mohs can require many visits back to the surgeon, until the edges of the cancer can be found.

In cases where the cancer removal has been excessive, a surgeon specializing in that region of the body may be required. For example, a colorectal surgeon may be required when surgery is necessary around the anus. A reconstructive urologist surgeon is often used on male EMPD cases that involve the scrotum, penis or other areas around the genitals.  

Having a team of physicians such as a Mohs surgeon and a reconstructive urologist, in the cases of men, is a common way to treat EMPD.  Women with EMPD often consult with a Mohs surgeon and a gynecologic oncologist.