Nodular lymphoid hyperplasia of urinary bladder admixed with non-invasive low-grade urothelial carcinoma

Primary malignant lymphoma of urinary bladder is extremely rare, and benign nodular lymphoid hyperplasia has not been reported in bladder. Nodular lymphoid hyperplasia of bladder associated with bladder carcinoma has also not been reported. Herein the author describe a 64-year-old man who presented with dysuria and his cystscopic examination revealed a papillary tumor in bladder. A transurethral resection of bladder tumor was carried out, and histopathologic examination revealed a non-invasive pTa low-grade papillary urothelial carcinoma and nodular lymphoid hyperplasia that were mixed up. The nodular lymphoid hyperplasia was composed of inner germinal centers and outer marginal and mantle zones. The germinal centers were composed of tangible body macrophages, centrocytes and centroblasts, while the outer zone of mature lymphocytes. Immunohistochemical profile of nodular lymphoid hyperplasia was as follows: cytokeratin AE1/AE3-, cytokeratin CAM5.2-, CD45+++, CD20+++, CD79a++, CD138-, CD3-, CD45RO-, CD15-, CD30-, p53- Ki67 80% (confined to germinal centers), bcl-2-, bcl-6++, CD10++, MUM1-, cyclinD1-, light chains-, CD56-, TdT-, CD68-. The patient is now followed up without any treatments by periodical cystscopy with BCG injection and cytology. No recurrence is noted 13 months after the first presentation. In conclusion, an extremely rare case of nodular lymphoid hyperplasia mixed with non-invasive urothelial carcinoma in bladder is reported.