Peninsula Dermatologic Surgery Mohs

321 Middlefield Road, Suite 245
Menlo Park, CA 94025
T 650.326.7222 F 650.326.7332


There are some skin cancers for which we do not recommend Mohs surgery. During traditional Mohs surgery, the tissue is frozen with liquid nitrogen. This quick process is great for identifying some tumors such as basal cell and squamous cell skin cancers. However, this process can make it difficult to identify certain cells and tumors such as melanoma under the microscope. In these cases, we often recommend a modified procedure called “Slow Mohs.”

The surgical part of “Slow Mohs” is exactly the same as regular Mohs surgery except that it is performed over a few days instead of a few hours. Just like Mohs, the surgery is done under local anesthesia in the office. The goals are also the same in that we want to give you the highest cure rate while sparing as much normal tissue as possible. The only difference is that instead of quickly freezing the tissue, it is sent to a lab and placed into a wax block overnight. Microscope slides or "permanent sections" are made the next morning for the dermatopathologist to read. This slow process preserves the identifying features of these tumors so that we can tell if the margins are clear. If cancer is still present, you will return to our office the next day and we will remove only that skin where the cancer remains. Once we are sure that no tumor remains, we will discuss your closure options with you.

With the "Slow Mohs" procedure, we typically reserve several 30-45 minute appointments for you over consecutive days.”