Seeding of a high-grade papillary urothelial carcinoma of the bladder along a nephroureterostomy tract

Percutaneous nephrostomy placement is a common treatment for obstructive uropathy of various causes. Although rare in the literature, tumor seeding along the nephrostomy tract is a potential risk of percutaneous nephrostomy in the treatment of obstructive symptoms secondary to urothelial carcinoma. In this case report, we present one such unusual outcome where urinary bladder urothelial cancer cells metastasized to the paravertebral soft tissues through apparent seeding along a nephroureterostomy tract.