TO THE DEATH OF GUESSWORK
Surgical oncology is to some extent a form of brinkmanship. The surgeon is juggling morbidity versus clearance every time a cancer is resected. While every tumor is “resectable,” it is often a matter of morbidity and mortality. For surgical outcomes, surgeons tend to focus on avoiding positive margins rather than over-resecting tumors and creating large defects. This is for good reason given that a missed positive margin can be devastating if not fatal for patients. However, making large holes for small tumors can likewise have devastating effects, particularly for lesions on the face where ongoing morbidity from neurovascular fallout, loss of function, and altered cosmesis can have a huge impact on patients’ lives. A technique where only the tumor is removed with a narrow—but clear—margin causing minimal morbidity has remained the holy grail for surgical oncologists. Margin control surgery (MCS) is the closest we have to achieving this in treating skin cancer.
Surgical brinkmanship comes in the form of educated guesswork. Tumors can be resected via two distinct philosophies:
To operate to anatomy. The surgeon removes an entire unit that encompasses the tumor.
To operate to pathology. The surgeon estimates the clinical margin of a tumor and the excision aims to excise just this.
Operating to anatomy is quite nuanced. In surgical oncology, lung cancers are a good example. With a pneumonectomy, instead of leaving behind a nonfunctioning lung and risking positive margins, it is often wiser to remove the whole lung lobe. Similarly, when dealing with a large basal cell carcinoma (BCC) on the nasal alar—occupying more than 50% of the alar—the surgeon will remove the entire alar skin to reconstruct the defect as per the subunit approach, so why not just remove the subunit as the first level? This approach is not tissue-sparing but usually removes the entire lesion with the first attempt.
These philosophies involve some form of guesswork. The central tenant of MCS is not to spare tissue or remove lesions in their entirety, it is to avoid guesswork.
All lesions undergoing MCS need a biopsy to confirm the diagnosis prior to a surgical procedure. This is usually done at the preassessment appointment; however, depending on necessity, biopsies of non-melanocytic lesions can be performed on the day of the surgery with a frozen section. Biopsy adds little morbidity or cost to the patient.
While an excisional biopsy is always a pathologist’s preference, this is not feasible for many lesions. Choosing whether to do a shave, curettage, punch, or surgical incisional biopsy is key and depends on the pathology, anatomic site, and patient factors (e.g., coagulation or healing issues). Without a reasonable understanding of skin pathology, the surgeon is not equipped to choose the appropriate method.
Generally, curettage should be reserved for BCCs ...