Mohs micrographic surgery is an advanced, highly effective technique used to treat common skin cancers, such as basal cell carcinoma and squamous cell carcinoma. The procedure involves removing cancer layer by layer and examining 100% of the tissue margins under a microscope to ensure complete removal while sparing healthy tissue. Despite high cure rates—up to 99% for new basal cell carcinomas—this specialized method has drawbacks. Prospective patients should carefully consider the unique logistical, physical, cosmetic, and financial disadvantages of the process.
Time Commitment and Logistical Burdens
The precision that defines Mohs surgery necessitates a significant time commitment from the patient on the day of the procedure. Unlike a standard surgical excision where the wound is closed immediately, Mohs is a multi-stage process where the patient must remain present between excisions. Each stage involves removing tissue, processing it, and microscopically examining the specimen, which can take an hour or more to complete.
If cancer cells are found, the patient returns for another removal stage, followed by another waiting period. This cycle continues until the margins are clear, meaning a single procedure can extend over several hours, often requiring a full day commitment. This prolonged waiting time can be a source of anxiety and stress. The requirement for a full-day commitment also involves logistical burdens, such as arranging transportation, taking time off work, and finding care for dependents.
Potential Physical Complications
While Mohs surgery carries certain medical risks common to any surgery involving skin incision, post-operative complications are rare. These can include bleeding, bruising, and the formation of a hematoma. Infection is another possible complication, with studies showing an occurrence rate of less than 1% to 2%.
A specific concern relates to the risk of nerve damage, particularly when the tumor is located on the face or head. Superficial sensory nerves may be severed during tumor removal, leading to temporary or permanent numbness in the area. When a tumor is deeply invasive, there is a small risk of affecting motor nerves that control muscle movement, which can result in muscle weakness or temporary paralysis. Pain and discomfort after the surgery are common but typically mild, depending on the size of the excision and the complexity of the subsequent reconstruction.
Scarring and Reconstructive Needs
The primary goal of Mohs surgery is to maximize tissue preservation, yet the complete removal of the skin cancer inevitably leaves a surgical defect that must be repaired. The final size and shape of the resulting wound are unpredictable until the procedure is complete, which can be distressing for patients. All surgical wounds result in a scar, and the final appearance is influenced by the patient’s healing ability and the location of the excision.
The closure of the defect often requires careful reconstruction, which may involve simple primary closure with stitches, or more complex techniques like a skin graft or a local flap. A skin graft involves transplanting skin from a distant site, while a local flap mobilizes adjacent healthy tissue to cover the wound. These procedures introduce additional scarring and can occasionally distort facial features, such as the eyelids or lips. Patients must manage expectations, as complete healing and the final scar appearance can take up to six months or longer.
Financial and Insurance Complexities
Mohs surgery is a highly specialized procedure, requiring fellowship-trained surgeons and a dedicated on-site laboratory for immediate tissue processing. This contributes to higher overall costs compared to standard excision. The financial burden is complex, often involving separate billing components for the surgeon’s professional fee, pathology services, and the facility fee. The cost for a procedure can vary significantly, depending on the number of stages required and the complexity of the reconstruction.
While most insurance plans, including Medicare, cover Mohs surgery as medically necessary, the patient’s out-of-pocket expenses can still be substantial. High deductibles, co-pays, and co-insurance amounts contribute to the financial strain, particularly for patients with less comprehensive plans. If a separate plastic surgeon is required for a complex reconstruction, this introduces an additional layer of billing and potential cost that may not be fully covered under the initial Mohs procedure’s authorization.