Melanoma of Unknown Primary Origin: A Case Report and Literature Review

MUP is an uncommon and challenging presentation of metastatic melanoma. Its pathogenesis remains unclear, although several theories, including immune-mediated regression of the primary lesion, have been proposed. MUP should be staged as stage IV disease and treated with the same systemic therapies used for stage IV MKP, including immune checkpoint inhibitors and targeted agents. Prompt recognition and standardized management are crucial to optimizing outcomes in this subset of patients.