Used to treat skin cancer, this very precise surgery is sometimes called by its full name, Mohs micrographic surgery. Physicians who perform it are specially trained dermatologists with a 
knowledge of cancer, pathology, and reconstructive surgery. Mohs surgery is the 1930s invention of Dr. Frederick Mohs, a University of Wisconsin professor of surgery.
knowledge of cancer, pathology, and reconstructive surgery. Mohs surgery is the 1930s invention of Dr. Frederick Mohs, a University of Wisconsin professor of surgery.
When Physicians Use Mohs
Most tumors that a dermatologist Palo Alto treats with Mohs surgery are complex growths of either basal or squamous cell cancers. While physicians sometimes use the technique to treat superficial melanoma, this is rare. Experts classify skin cancer as complex under one or more conditions:
• It occurs in an area where maximizing function and appearance is crucial, such as the nose, lips, and ears.
• It develops in an area with above-average recurrence risk, like the temples or eyelids.
• It has recurred after initial treatment or had incomplete treatment.
• The tumor is large.
• Edges are not clearly definable.
• There is scar tissue in the area of the cancer.
• The malignancy develops in an area that has received radiation.
• The individual is immunosuppressed due to circumstances such as an organ transplant or certain types of leukemia.
• A patient is prone to developing multiple instances of skin malignancies.
How This Surgery Works
Administration of a local anesthetic is the first step in the procedure. Once the skin is numb, the physician scrapes the tumor with a curette to help determine the margin between malignant and normal tissue.
The surgeon systematically removes thin layers of tissue, using an electric needle as necessary to halt bleeding. Tissue is mapped regarding its precise location on the body using a labeling 
and color-coding system.
and color-coding system.
Each tissue section is processed and examined by the physician, who is looking for any sign of remaining cancer cells. Processing and examination of each tissue section takes about an hour, during which the patient is usually able to leave the facility.
If the surgeon spots malignant cells at the margin of the tissue, the patient must return. Matching the tissue to the map, the physician removes additional layers and repeats the processing and examination stages until sure that all the cancer has been removed. The final step in Mohs surgery is reconstructing any skin defect with stitches, a skin graft, or a flap.
The cure rate for new cancers is more than 99 percent. For recurrent malignancies, the Mohs success rate is 95 percent.
