Non-Amputative Digit Preservation Surgery versus Amputation in Nail Unit Melanoma: A Retrospective Study in Mexico and Brazil.

Introduction: Nail unit melanoma (NUM) is a rare but aggressive malignancy with historically poor outcomes. Currently, there are no treatment guidelines for NUM. Methods: A retrospective analysis was conducted on patients diagnosed with NUM in Mexico and Brazil. Clinical and histopathological data were reviewed, and outcomes were compared between those who underwent amputation versus digit preservation surgery. Survival rates, recurrence, and functional status were assessed. Results: A total of 75 patients from Mexico (51.9%) and Brazil (48.1%) were evaluated. Clinical and pathological characteristics were similar between both groups. Functional surgery was performed in 40 patients (49.4%), including six with invasive melanomas. The median follow-up was 50.3 months (95% CI: 29.4-71.3, SE: 10.7). Among the 7 patients with invasive melanomas who underwent functional surgery, one experienced a recurrence, and one died from a cerebrovascular accident. The remaining 5 patients are alive and disease-free, with follow-up periods ranging from 1 to 27 months. Conclusions: Non-amputative surgery may be a safe alternative for thin NUMs, reducing amputation-related morbidity. Long-term follow-up and larger studies are needed to confirm guidelines.