Low Recurrence Observed in MIS Cases With Clear Biopsy Margins

Key Takeaways

• Diagnostic excisional biopsy alone may be sufficient to treat select cases of melanoma in situ (MIS) that are neither lentigo maligna (LM) nor acral lentiginous melanoma (ALM) subtypes.

• Patients with clear margins on excisional biopsy showed no recurrences.

• Researchers reported no cases of metastasis or melanoma-specific death.

A new retrospective cohort study suggests that diagnostic excisional biopsy alone maya be efficacious for select cases of melanoma in situ (MIS) that are neither lentigo maligna (LM) nor acral lentiginous melanoma (ALM) subtypes.

Researchers publishing in JAMA Dermatology conducted the study at the Skin Cancer and Melanoma Unit of Andreas Sygros University Hospital in Athens. The team evaluated 403 lesions in 401 patients diagnosed with non-LM/non-ALM MIS between 1991 and 2023 (media follow-up, 5.2 years). All patients had at least 1 year of documented follow-up, and individuals with a history of invasive melanoma or in situ LM or ALM were excluded. Most lesions were located on the trunk (49.9%), followed by the lower (24.6%) and upper extremities (17.6%). Excisional biopsy was performed as initial management in all cases; wide excision was performed in 92.3% of lesions.

There was just one case of local recurrence, occurring in a patient with positive margins on initial biopsy who did not undergo wide excision. The lesion progressed to invasive melanoma within 14 months. No local recurrences occurred over a median follow-up of 8.1 years among the 30 patients with clear excisional biopsy margins who did not receive further intervention.

No recurrences among There were no recurrences among the 23 lesions treated with narrow excision margins averaging 0.36 cm (median of 4.3 years). Histopathology confirmed that six suspected recurrences near excision scars were benign lesions such as nevi or solar lentigo. No cases of metastasis or melanoma-specific death were reported during follow-up.

"Diagnostic excisional biopsies with clear margins may be sufficient for treating MIS; however, larger studies are necessary," the authors wrote.

Sources:

Dessinioti C, et al. JAMA Dermatology. 2025. doi:10.1001/jamadermatol.2025.3054