Comparison of Disease Progression Between Amelanotic Melanoma and Melanotic Melanoma

Amelanotic melanoma lacks melanin and is more challenging to diagnose than pigmented melanoma, often leading to delayed detection and worse outcomes. We conducted a retrospective cohort study of 322 patients (28 with amelanotic melanoma and 294 with melanotic melanoma) treated at Sheba Medical Center between 2017 and 2023. Clinical features, treatment modalities, and 1-year outcomes were analyzed. Tumor stage at diagnosis was the strongest predictor of remission, disease progression, and mortality in both groups. Pigmentation was associated with a higher likelihood of treatment modification (p = 0.02) and showed a borderline association with progression (p = 0.08). Subgroup analysis by stage revealed no significant outcome differences except for increased therapy change in stage 2 melanotic melanoma. The findings reinforce the importance of early detection, especially in amelanotic melanoma.