Clear Cell Adenocarcinoma of the Urinary Tract Arising in a Young Man With the Congenital Malformation Disorder Opitz Syndrome: A Case Report.

This article focuses on a rare case of clear cell adenocarcinoma of the urinary tract, a Müllerian-type tumor subtype of urethral/bladder cancer, occurring in a male patient with Opitz syndrome, a congenital disorder affecting urogenital development. Clear cell adenocarcinoma is typically more aggressive, predominantly affects females, and is associated with abnormal embryological remnants such as Müllerian and Wolffian ducts. The patient presented with a pelvic mass and pulmonary metastases, with diagnosis confirmed by imaging, histology, and immunohistochemistry. Treatment included pembrolizumab and palliative radiation, with partial response observed. This case represents the first reported instance of a Müllerian-type urothelial tumor in a male with a congenital urogenital malformation, underscoring the potential link between congenital urinary anomalies and rare urinary tract malignancies.