Pyeloureteral filling defects associated with systemic anticoagulation: a case report.

The etiology of pyeloureteritis cystica has long been attributed to chronic infection and inflammation. A case is presented that is unique in that the acute onset and the rapid resolution of pyeloureteral filling defects in this patient were documented by radiography. There is no evidence of antecedent or concurrent infection in this patient. The disease occurred subsequent to the initiation of heparin therapy for suspected pelvic thrombophlebitis and cleared rapidly subsequent to its discontinuation. The rate of resolution of the radiographic findings may be helpful in distinguishing between true pyeloureteritis cystica and submucosal hemorrhage.