[Transitional carcinomas of the urinary tract: synchronous and metachronous lesions]

The urothelium is a pseudostratified cylindrical epithelium that lines the calices, renal pelvis, urethers, bladder, part of the urethra and part of the prostate ducts. Transitional cell carcinoma (TCC) is a malignant neoplasia that can appear in any site where urothelium is present, being the bladder the most frequently affected organ. We performed an analysis of our experience and conducted a literature-based metanalysis to evaluate the coexistence of tumoral lesions at different locations in the urinary tract.

Between 1983 and 1993, 397 patients with TCC lesions involving the upper urinary tract (UUT), bladder, urethra or prostate, were diagnosed and treated. Coexistence, either synchronic or metachronic, of several lesions in different sites of the urinary tract was considered as a multiple tumor.

Overall, 440 tumors were diagnosed in 397 patients. A single lesion appeared in 360 patients, while 37 presented multiple locations with a total of 79 tumors. The lesions were located at the following levels: 17 renal, 21 uretheral, 372 vesical, 13 in the urethra and 17 in the prostate ducts. According to the location, the frequency of single lesions was: UUT 58%, bladder 91%, urethra 8% and prostate ducts 35%. Synchronic UUT and intravesical tract tumors develops in 1% and 4% of patients with bladder TCC, respectively. Two percent of vesical tumors showed metachronic relationship with UUT tumors and the same rate was seen for intravesical lesions.

Urothelial UUT tumors have a typical nosologic entity with specific features. Their coexistence with vesical tumors is frequent. When tumors of the bladder occur after a UUT tumor the interval of highest incidence between diagnoses is 2-3 years, and there are no histological risk factors among them for prognosis. Transitional cell prostatic urethral tumors are most often secondary to histologically similar, poor prognosis, bladder tumors, and usually synchronic.