Excising melanoma in situ (MIS) with a 5-mm margin on low-risk body sites had a low rate of recurrence, according to a study published in JAMA Dermatology. The authors conducted a case series examining all MIS lesions from a single private dermatology clinic from January 2011 to November 2018. The researchers gathered data from 351 MISs from 292 patients; 50.4%, 30.5%, and 19.1% of the lesions were superficial spreading melanoma, lentigo maligna, and lentiginous MIS, respectively. The lesions were mostly located on the trunk, followed by upper limb and lower limb (47.9%, 27.4%, and 16.8%, respectively); only two lesions (0.6%) were located on the scalp. The researchers found that most of the lesions were small, with 78.1% and 88.9% having a length and width less than 10 mm, respectively. Following the current guidelines, after excision with a 5-mm clinical margin, 99.1% of lesions did not have clinical recurrence. Only three lesions (0.9%) had local recurrence, with no metastatic spread observed.
