The Risks of Mohs Surgery

Each patient is unique… however, there are some common risks.

• The exact size of the final defect, following clearance, cannot be predicted prior to surgery. The tumour may be much larger than estimated from the surface appearance.
• A scar will remain at the site of removal. Every effort is made to obtain optimum cosmetic results, but the primary goal is always to remove the entire tumour.
• As a patient, you should understand there is no absolute guarantee that any procedure will be totally free of complications or adverse reactions.
  There may be loss of motor (muscle) or sensory (feeling) nerve function. In the rare instance where tumour involves nerve fibres, the nerves must be removed along with the tumour. If a sensory nerve is injured or removed, numbness results. Sensation will usually, but not always, return. If a motor nerve is involved, the patient may be unable to move the muscle that the nerve served. In some, but not all cases, this nerve function will return after a long period. Rarely, a few patients experience intermittent shooting pain at the surgical area. However, this is a very unusual complication.
• The tumour may involve an important structure. Because tumours often occur in the head and neck, many are near or on vital structures such as the eyes, nose or lips. In such cases, portions of these structures may have to be removed with resulting cosmetic or functional deformities.
• The surgical area may remain tender for several weeks or months after surgery, especially if large amounts of tissue were removed.
• Skin grafts and flaps used to cover surgical areas may occasionally not survive.