Levodopa and melanoma: three cases and review of literature.

Three patients are reported who developed a melanoma while taking levodopa for Parkinson's disease. There were two cutaneous melanomas and one metastatic melanoma with occult primary. The literature on the association of Parkinson's disease, levodopa therapy and melanoma is reviewed. The capacity of levodopa to induce melanomas and its alleged adverse effect on the clinical course of the disease are questioned.