++
Margin control surgery (MCS) can be used in the management of practically any skin lesion, though in multifocal tumors or pathologies with a high incidence of satellite lesions, the importance of surgical margins is diminished. In these scenarios, MCS may serve as an adjunct to guide radical excision and reduce unnecessary morbidity.
++
Before discussing indications, it is worth noting some key barriers to the utilization of MCS.
++
In his best-selling book Thinking, Fast and Slow, celebrated economist and psychologist Daniel Kahneman described two distinct ways, or paradigms, that our brains use to formulate decisions. In the first paradigm, we make decisions quickly, automatically, stereotypically, and unconsciously. This is the system that many surgeons typically use when excising a given skin tumor. They read the biopsy and histopathologic diagnosis and proceed briskly to a wide local excision (WLE) with the measured margin guideline detailed in a range of protocols. They’ve done this procedure many times before, they’re familiar with its demands and confident that their experience will set them in good stead. In contrast, the second way that the brain formulates a decision is slow, effortful, logical, calculating, and conscious. This slow-thinking paradigm is more suitable when considering the many potentially complex aspects of MCS such as the available guidelines, the levels of the excision, coordination of the laboratory team, interpretation of the pathology and margin assessment, time constraints, as well as the integration of all these factors into a reconstruction plan. Human nature is always tempted to go with the fast system. It is knee-jerk, instinctual, and easier. Significant effort is required to resist this temptation and instead synthesize a surgical solution using the more measured contemplation of MCS.
++
Another barrier to MCS is the lack of facilities and appropriately trained specialists who can perform the procedure. Most pathology laboratories process frozen sections and routine skin excisions, but far fewer have the incentive or knowledge to process specimens with the level of precision needed for complete margin assessment. Similarly, surgeons tend to send a specimen off to the laboratory without a clear description of their expectations and may not understand the limits of traditional pathological margin assessment. To run an MCS service, a clear understanding of the entire process is ideal, and though perhaps daunting, this is achievable for most skin surgeons and pathology laboratories.
++
Constraints in funding and resources are unfortunately serious barriers in certain practice settings. Even in well-resourced settings, criteria have been defined as to when MCS is recommended or appropriate for common skin tumors. While a variety of different indication guidelines have been developed internationally, in many parts of the world there are no well-established criteria. In some countries, the national Mohs micrographic surgery (MMS) community has established criteria. Insurers and managers are eager to apply such guidelines when regulating access and making decisions to fund resource-intensive techniques.
...