The researchers concluded that the complete histopathologic removal of nearly nine of 10 DN using a peripheral margin of 2 mm of normal skin and a depth at the dermis and subcutaneous fat junction has the potential to decrease second procedures at DN biopsy sites, thereby decreasing patient morbidity.
According to researchers, such margin guidelines are needed because as many as two-thirds of the hundreds of thousands of suspicious skin moles removed each year in the United States require re-excision. Physicians warn that second procedures introduce more risk of infection, bleeding, and scarring, as well as inconvenience and unnecessary costs.
“Although the vast majority of suspicious-looking skin moles do not turn out to be cancerous melanomas, once a decision has been made to remove a mole, there should be a clearer standard margin,” said senior study investigator and dermatologist Dr. David Polsky, in a press release. Currently, he says, most physicians excise either just the darkest portion of a suspicious mole, or when removing the entire mole, opt for a small, imprecise 1 mm margin around the mole’s edge.
“Our study shows that a ‘one and done’ approach with a clearly defined, slightly larger margin is safer and more effective in completely removing suspicious moles with a single procedure than the current non-standardized approach,” said Dr. Polsky, the Alfred W. Kopf, MD, professor of dermatologic oncology at NYU Langone and director of its pigmented lesion section in the Ronald O. Perlman Department of Dermatology.
Dr. Polsky and his colleagues removed 151 suspicious skin moles in 138 men and women. Most biopsies came from the arms, legs, and backs.
All patients underwent the biopsy procedure, involving complete mole removal with a 2 mm margin, between January and August 2015. Researchers then monitored the patients for close to a year and a half after their procedures and found that none had any further suspicious growths at their biopsy sites.
Lab testing showed that more than 90% of biopsied moles were completely removed by using the single procedure, with 11 (7%) diagnosed as melanoma.
“While our study did not directly compare use of the wider margin to a narrower margin, the common practice of removing moles with narrow margins and performing a second ‘clean-up’ procedure suggests a need to move toward wider margins during the initial procedure,” said Dr. Polsky.
Dr. Polsky said if further data support the current findings, he hopes that other cancer centres will also adopt his “one and done” approach, and, if so, he will recommend changes to the next edition of practice guidelines issued by the American Academy of Dermatology.