I Had Mohs Surgery on my Scalp Which Left Me with a Bald Spot. Is This Common?

Injury to the follicles can result in hair loss. Express your concerns with your surgeon so that options to salvage hair follicles can be provided. Raffy Karamanoukian, Los Angeles

If you have a skin cancer on the scalp excised (cut out) whether with Mohs surgery or a conventional excision, and the wound is allowed to heal on its own over several weeks, then you will be guaranteed to develop a bald spot.  If the wound were reconstructed with stitches, and not a skin graft (patch) then there is a very good chance that hair-bearing skin from the adjacent field around the surgical defect can be used to close the wound with normal hair growth.  There can be a temporary loss of hairs making the scalp look bald in a focal area for a few months after surgery. This telogen effluvium often occurs about three months after surgery but corrects itself as new hairs grow out.

Yes, this is common, but can usually be fixed or at least improved (made smaller) if you desire.  Please discuss this with your treating Dermatologist.

Freezing or burning of a skin cancer are other alternatives; however, Mohs will give the highest cure rate and preserve the greatest amount of healthy tissue. The two other alternatives that you mention would actually have a higher risk of scarring or damage to the surrounding hair. The "baldness" is not related to the Mohs surgery. It is most likely related to the repair that was done afterwards. It's unclear as to how long ago the procedure was performed but sometimes you can have some temporary hairloss afterwards. This is because the nearby hairs were put into a sleep phase and shed after the procedure. In that case the hairs start to return 3-6 months later. If the surrounding hairs were physically damaged during the repair process the hair loss may be more long-lasting. Talk to the doctor who performed the surgery as to what is the cause of the baldness and what if anything can be done.

Mohs surgery remains the best option for treatment of a skin cancer on a hair bearing area.  Because Mohs surgery is tissue sparing, the final defect is more likely to be shallower and smaller then with a standard excision yet lead to the complete tumor removal. 

On occasion, shallow wounds on scalp with intact hair follicles are allowed to heal on their own. Since hair follicles are necessary for hair regrowth, the wound is then covered by the newly grown hair. If the depth of the wound was deeper than the location of hair follicles, then the area will be bold unless reconstructed with stitches. However, a form of reconstruction called skin grafting will also result in a bold spot.

With regards to your current tumor, you may want to ask your surgeon to consider stitching the area to minimize the risk of the bold spot formation. The bold area may also be excised and reconstructed so that you have as little hair loss as possible.