WEDNESDAY, Sept. 3, 2025 (HealthDay News) -- For treating melanoma in situ (MIS), diagnostic excisional biopsies with clear margins may be sufficient, according to a study published online Sept. 3 in JAMA Dermatology.

Clio Dessinioti, M.D., from Andreas Sygros Hospital in Athens, Greece, and colleagues examined local recurrence and prognosis in non-lentigo maligna (non-LM)/non-acral lentiginous melanoma (non-ALM) MIS in a retrospective cohort study involving patients diagnosed from 1991 to 2023 who were followed up for at least one year. The analysis included 401 patients with 403 non-LM/non-ALM MIS.

The researchers found that excisional biopsy was initially used for treatment for all lesions, followed by wide excision for 92.3 percent. Only one local recurrence occurred in a patient with involved margins at the excisional biopsy who did not undergo wide excision; an invasive melanoma developed 14 months later. Clear excisional biopsy margins with no wide excision were seen for 30 lesions in 30 patients; they had no recurrence at a median of 8.1 years of follow-up. No recurrences occurred at a median follow-up of 4.3 years among 23 patients with 23 lesions with wide excision with margins that were narrower than the standard 0.5 cm. Six patients (1.5 percent) developed a lesion suspicious for recurrence near the excision scar during follow-up, which was excised; on histopathology, this showed nevus or solar lentigo. There were no metastases observed or melanoma-specific deaths reported.

"These findings provide support that non-LM/non-ALM MIS excised with clear histopathological margins in the excisional biopsy may not require additional treatment," the authors write.

One author disclosed ties to the biopharmaceutical industry.

Abstract/Full Text

Editorial