Association of renal adenocarcinoma and BK virus nephropathy post transplantation.

While most BK virus infections are asymptomatic, immunosuppression has been associated with BK virus reactivation and impaired graft function or ureteric ulceration in renal transplant patients and hemorrhagic cystitis in bone marrow transplant patients. Oncogenicity is also postulated and this is the first report of a child with a carcinoma of the donor renal pelvis following BK virus allograft nephropathy. Removal of the primary tumor and cessation of immunosuppression led to regression of secondary tumors and a return to health.