Division of Hematology-Oncology, Department of Internal Medicine, Yeouido St Mary's Hospital, Catholic University of Korea, Seoul, Korea.
A 40-year-old woman presented to our emergency room with a bleeding tendency and thrombocytopenia. Ten days ago, she was diagnosed with immune thrombocytopenic purpura (ITP) at another hospital after a complete hematologic work-up, including bone marrow biopsy. Despite high-dose steroid treatment (dexamethasone 40 mg/day for 4 days), the platelet count did not rise. Even after administering intravenous immunoglobulin (120 g/day for 2 days) the platelet count declined to 5,000/mm3. She received single-dose vincristine (1 mg) for gross hematuria and was then transferred to our hospital. Upon admission, she showed anuria and a sharp increase in creatinine levels but no evidence of microangiopathic hemolytic anemia. Abdominopelvic computed tomography (CT) revealed hyperdensity at the bilateral renal pelvis extending into the upper ureters (