Primary Melanoma of the Extremity

Cutaneous melanoma is the most aggressive malignancy in skin cancers. Cutaneous melanoma is a rare disease in Taiwan with an incidence rate of around 1/100,000. Acral lentiginous melanoma is the most common subtype and comprises more than half of cutaneous melanoma in Asia including Taiwan but only 1% in Caucasians. In addition, mucosal melanoma accounts for more than 20% of malignancy melanoma in Taiwan but only 1% in Caucasians. Acral and mucosal melanomas have distinct epidemiological, clinical, pathological and genetic features from non-acral melanoma which is commonly seen in Western countries. Comparing with melanoma in Caucasians, Asian melanoma has higher recurrence rate after primary surgery, lower response rate to immunotherapy, and shorter progression-free survival for immunotherapy and targeted therapy leading generally poor survival outcomes regardless stage.