Transitional Cell Carcinoma Arising From the Renal Allograft: A Case Series and Review of the Literature.

Transitional cell carcinoma (TCC) of the urinary tract appears more commonly among the transplant population. The increased incidence of TCC has been primarily associated with the male gender, BK virus (BKV), and smoking. We report a case series and comprehensive review of the literature. The comprehensive literature review was conducted via Pubmed using the keywords "transitional cell carcinoma" and "renal allograft." At our institution, all of our cases presented with hematuria, and hydronephrosis was present in 50% (two) of our cases. BKV was detected in 75% (three) of our cases. The average time from BKV detection to TCC diagnosis was 5.6 years. The average time from transplant to TCC diagnosis was 11.25 years. Upon review of the literature, a total of 20 cases were reported of TCC arising within the renal allograft. Of those patients, 55% (11) presented with hematuria, 30% (six) had BKV, and 35% (seven) were found to have hydronephrosis. The average time from BKV detection to TCC diagnosis was 3.4 years and the average time from transplant to TCC diagnosis was 9.5 years. Given the relatively increased incidence of neoplasm among solid organ transplant recipients, painless hematuria in a renal transplant recipient should raise concern for malignancy, especially in those with prior oncogenic viral infections, history of smoking, other environmental exposures, or in those with high cumulative doses of immunosuppressive medications.