BK virus associated pronounced hemorrhagic cystoureteritis after bone marrow transplantation.

Ureteral stenosis due to reactivation of the BK virus (BKV) in a state of immunodeficiency is very rare. More common is the appearance of a hemorrhagic cystitis. This report not only shows bilateral ureteral stenosis after bone marrow transplantation, but also presents severe complications as chronic pelvic pain and impaired kidney function as well as irreparable damage to the whole urinary tract leading to nephroureterectomy, subtrigonal cystectomy and orthotopic ileal neobladder. Finally renal transplantation was required. To our knowledge this is the first case in the literature where such a severe course of BKV associated hemorrhagic cystoureteritis is described.