Possible Complications of Mohs Surgery

Mohs surgery is a specific surgical technique used to remove cancers of the skin. This type of surgical procedure involves minimal loss of healthy tissue in comparison to the standard surgical excision of the skin. The cure rate for basal skin carcinoma with the Mohs surgery is normally higher than 99 percent, with usually less than a 1 percent chance of recurrence.

Allergic Reaction

An allergic reaction can occur with the local anesthesia or bandage products. Allergies to suture materials are rare.


Bleeding is a possible complication with Mohs surgery. Any medications or substances that could increase the risk for bleeding should be stopped prior to the surgery, such as aspirin or other anti-inflammatory agents, alcohol, vitamin E and fish oil supplements. It is important to advise the surgeon of all medications that are being taken, as well as give all information regarding medical history. Always follow the surgeon's instructions involving the dosage of medications prior to surgery.

When the wound is kept clean, and proper post-operative care is practiced, it is less likely that bleeding will occur. Normally, bleeding may happen with repairs, especially if a larger area is involved.

Pain, Swelling and/or Bruising

Swelling and bruising is common following Mohs surgery, especially if the areas that are being treated are around the mouth, eyes or lips. Puffiness around these areas could last for 2 to 3 months. Some redness around the wound and tenderness or tightness is also expected, and will normally disappear within one to two weeks.

Delayed Healing

Immunosuppression (impairment of the immune system) and bleeding disorders may cause delayed healing.

Damage to Adjacent Tissues

Sometimes, adjacent tissue could become damaged.


There is the possibility of scarring, as with most surgeries, but with Mohs surgery, the scars are normally smaller because less of the healthy skin is removed (and the damaged skin is taken away in layers).

Nerve Damage

When layers of tissue are removed, there is the risk of nerve damage. This is common and the numbness is usually temporary until the nerve fibers grow back. Rarely, it may become permanent and paralysis may occur.


There is a possibility of disfigurement, but this is rare with Mohs surgery because of its precise and specialized removal, leaving healthy tissue in tact.


As with any surgery, Mohs surgery does impose a risk of infection. This possibility is greatly minimized if the area of treatment is kept sterile. For individuals that are prone to infections, such as persons with diabetes or for larger wounds, antibiotics may be necessary. These are normally given before the surgery “prophylactic antibiotic treatment”.

Anesthetic Reaction

As with any surgical procedure, there is a risk of an anesthetic reaction.

Possibility of Recurrence of Cancer

Although the procedure has a high cure rate and very low recurrence possibility, as with any form of cancer, there is always the potential for a recurrence.

Graft Failure

Repairs with grafting may be needed, especially when complications occur such as a seroma (pocket of clear serous fluid that develops after a surgery), hematoma (collection of blood usually clotted) or necrosis (death of cells or tissue from the interruption of blood). A possible need for additional surgery can occur.


As with any surgical procedure, there is a possibility of necrosis.

Hyperpigmentation or Hypopigmentation of the Skin

Color changes of the skin can occur after Mohs surgery. Hyperpigmentation is more common with darker skinned patients.

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