Possibility of spontaneous seeding of transitional cell carcinoma of the ureter in renal tubules: another mechanism of transitional cell carcinoma dissemination.

Cancer cell seeding inside the urinary tract always has been considered one possible mechanism of the multicentric origin of transitional cell carcinoma (TCC). However, there is still no direct clinical evidence to prove that the natural seeding of TCC is a real event. To our knowledge, we report the first case of spontaneous seeding of TCC of the ureter in the renal tubules of a hydronephrotic kidney. The TCC nature of the intratubular tumor cells has been confirmed by the morphological appearance of them after hematoxylin and eosin staining and positive p53 immunohistochemical staining.