Malignant melanoma of the male urethra with increased 5--cysteinyldopa: A case report.

Introduction: We herein present a case of malignant melanoma of the male urethra with an increased serum 5--cysteinyldopa concentration.

Case Presentation: A 77-year-old man visited our hospital complaining dysuria and a dark brown mass protruding from the external urethral meatus. His serum 5--cysteinyldopa concentration was elevated beyond the upper limit of the reference range.