What is Mohs surgery?

Mohs surgery is a very effective technique for treating skin cancer. Its difference with other treatments is that it allows an immediate microscopic examination of the tumor and it is possible to eliminate all the roots of the cancer and therefore its extension.

Some cancers spread thanks to these roots into the skin, blood vessels, nerves or cartilage, and thus manage to reappear once removed. By removing these roots, Mohs surgery prevents the cancer from growing again and that is why this surgery achieves higher cure rates.

Another of its advantages is that it only removes the tumor tissue, respecting the healthy tissue, so the best aesthetic results are also achieved.


The disadvantage of Mohs surgery is that it is not possible to know how long the procedure will last, since it is not possible to predict the number of roots that the tumor will present.


This surgery is not suitable for all types of skin cancer, but is used for:

– A skin cancer that has appeared again after previous treatment.

– Cancer located in areas prone to tumor reproduction.

– Histological types that are more aggressive and more likely to recur.

– A cancer located in an area where the aesthetic result is a “priority”.

Generally, these conditions mean that Mohs surgery is usually used for cancers in the nose, lips, eyelids and genitals.

The process up to healing

Mohs surgery is performed in a properly prepared medical center. The patient receives only local anesthesia, so he/she is awake, and the area to be treated is sterilized and marked. The dermatologist removes the visible cancer and a thin layer of additional tissue.

See also  Hemangiomas, birthmarks

This excised tissue is cut into sections, the edges are stained and the pieces are marked and then frozen in liquid nitrogen. A technician then makes one thin slice from the edge and bottom of the piece, and these are placed on glass slides to be stained and viewed under a microscope.

The pathologist then examines the edges of each piece and this allows him to identify the roots of the cancer. If residual tumor is detected, a second excision is performed, although only where the tumor has developed.

This process is repeated until all the cancer roots have been located and removed. Once all of the cancer has been removed, the dermatologist may choose to:

– Let it heal naturally

– Close the defect with a direct suture

– Perform a skin graft

– Perform a skin flap.

Depending on the type of closure that has been performed, wound healing may take more or less time, although in most cases, it takes 7 to 10 days to remove the stitches.