ABSTRACT
Mesonephric carcinoma is a tumor entity that rarely develops in the neck of the uterus and vaginal wall and is extremely unusual in the urinary bladder or paraurethral tissue. The tumors arise in the remnants of the wolffian or mesonephric duct. The malignant potential is considered to be lower than in tumors of the urethra with different histologic findings. Anterior pelvic exenteration is recommended in the literature as the treatment of choice. In the case described here, the tumor presented as a space-occupying lesion in a urethral diverticulum exhibiting striking clinical features of macrohematuria and urinary retention with subvesical obstruction of the urethra. In accordance with reports in the literature, cystectomy was performed and a Kock pouch constructed for urinary diversion. Tumors occurring in a diverticulum-and in this case manifesting as the rare tumor form of mesonephric carcinoma-should always be included in the differential diagnosis of macrohematuria in women.