C208: Mesonephroid adenocarcinoma of the urinary bladder - rarity in urology

C208: Mesonephroid adenocarcinoma of the urinary bladder - rarity in urology Bannowsky A.1, Osmonov D.2, Ückert S.3, Van Ahlen H.1 1

Klinikum Osnabrück, Dept. of Urology, Osnabrück, Germany, 2University Hospital Schleswig-Holstein, Campus Kiel, Dept. of Urology, Kiel, Germany, 3Hannover Medical School, Dept. of Urology, Hannover, Germany INTRODUCTION & OBJECTIVES: Mesonephroid adenocarcinoma of the urinary bladder presents an extreme rarity in urology with only 10 reported cases. They can probably be considered as the malign counterpart of nephrogenic adenoma. Mesonephroid adenocarcinoma of the ovary are quite common and are also known to occur in congenital urethral diverticuli in females. MATERIAL & METHODS: We report another case of a mesonephroid carcinoma in a 67 year-old male patient, which was treated by radical cystectomy, including a sigma resection due to an intraoperatively established infiltration of the tumor into the sigmoid colon. Histologically we discovered an extensive and invasive, moderately differentiated adenocarcinoma, which histomorphologically and immunohistochemically corresponded to a mesonephroid carcinoma (tumorstage pT4 pN0 M0 G2). RESULTS: Apart from the regular urothelium there are significant focal irregularities in the lamination with polymorphous and dyschromatic, highly enlarged karyons in all epithelial layers. The urinary bladder is infiltrated by a glandular, tubular and papillary tumor consisting of cells with clear cytoplasm and dyschromatic, polymorphous karyons with prominent nucleoli. Numerous atypical mitosis figures and hyperchromatic giant nuclei as well as occasional multinucleated tumor cells infiltrate down into the perivesical tissue without any urothelial differentiation. In the immunohistochemical evaluation the tumor cells consistently show a strong expression of cytokeratin 7 and cytokeratin 19, a clear reactivity with the antibodies Cam5.2 and 34BetaE12 as well as a focal expression of cytokeratin 20. CONCLUSIONS: Mesonephroid adenocarcinoma can show an invasive and extremely aggressive growth, leading to the indication for radical surgery at an early stage. Superficial tumors can be controlled by means of complete transurethral resection. In one case, a mesonephroid adenocarcinoma was successfully treated by means of adjuvant polychemotherapy. However, there is no sufficient evidence of the long-term success. The radiosensitivity remains unknown to date. Due to the organ-transgressing growth of the tumor in our patient, we perform systemic, adjuvant chemotherapy and periodical follow-ups to treat any progression at an early stage by renewed surgical intervention. Eur Urol Suppl 2014; 13(6) e1376