[Low-grade urothelial carcinoma of the bladder with osteoclast-like differentiation as part of primary multiple malignancies. Case report and literature review].

Low-grade urothelial carcinoma of the bladder with an atypical stromal reaction and accumulation of osteoclast-like giant cells is a rare form of urothelial cancer. A meta-analysis of literature data over the past 53 years revealed 30 publications containing a total of 50 cases of this form of urothelial cancer. In 2/3 of the cases, the primary tumor was located in the bladder, while the remaining cases were located in the renal pelvis. The disease is extremely aggressive: the median survival time is 12 months, and distant metastases are detected in 65% of cases. The article describes a clinical case of a patient with primary multiple synchronous cancers, including poorly differentiated urothelial carcinoma with osteoclast-like differentiation of the bladder, papillary renal carcinoma, and acinar adenocarcinoma of the prostate.