Abstract
Clear cell adenocarcinoma of the urinary tract is a rare subtype of urethral/bladder cancer that is classified as a Müllerian-type tumor and is typically associated with more aggressive behavior and worse prognosis. Individuals with underlying congenital defects involving the urinary system are known to be at an increased risk for bladder cancer in general; however, it is currently unknown whether patients with aberrant Müllerian and Wolffian duct regression and/or persistence, in addition to urinary anomalies, are at an increased risk for developing Müllerian-associated urinary tumors. In this case report, we present an extremely rare and unusual diagnosis of clear cell adenocarcinoma of the urinary tract arising in a male individual with Opitz syndrome, a congenital malformation disorder affecting multiple organ systems, including urogenital development. This presentation represents the first report of a urothelial tumor of Müllerian type occurring in a male individual with a urogenital congenital disorder.