Spontaneous Perirenal Hematoma in Idiopathic Thrombocytopenic Purpura 503 FIG. 1. Computed tomography scan showing bilateral perirenal hematoma. FIG. 3. Postoperative computed tomography scan 9 weeks after the diagnosis of perirenal hematoma. FIG. 2. Computed tomography scan showing a 20-mm distal ureteral stone. left costovertebral angle tenderness in addition to diffuse petechiae all over his body. In his biochemical analysis, blood urea nitrogen (53 mg/dl), creatinine (3.2 mg/dl), and fasting blood sugar (167 mg/dl) levels were also measured. Escherichia coli was detected in the urine culture, and the urinalysis revealed microscopic hematuria and pyuria. The results of the complete blood count analysis were as fol- lows: white blood cells 27,000/mm3, hemoglobin 12.2 g/dl, hematocrit 37.3%, platelet count 4,000/mm3, prothrombin time 16.6 seconds (9 to 14), and international normalized ratio 1.36 (0.8 to 1.19). Owing to suddenly evolving macroscopic hematuria, the patient received prednisolone (80 mg/d) and intravenous immune globulin (0.5 g/kg/d) (KIOVIG 10 g/100 ml-Eczacı- başı-Baxter), and an ultrasound examination of the uri- nary system demonstrated right and left perirenal hema- toma and irregular renal contours. A non-contrast com- puted tomography (CT) scan was then performed. The CT FIG. 4. Postoperative magnetic resonance imaging study. scan revealed a right perirenal hematoma with dimensions of 21×20×42 mm, a 15-mm stone in the right distal ureter without any marked ectasia, a left perirenal hematoma with dimensions of 150×120×90 mm (Fig. 1), left distal ure- teral ectasia, and a 20-mm distal ureteral stone (Fig. 2). The patient had an extremely low hematocrit (22%), hemoglo- bin (7.2 g/dl), and platelet counts (3,000/mm3) and received 6 IU erythrocytes and 3 IU platelets to improve his hemato- logic status. An operation was performed for his distal ure- 3 teral stones when his platelet counts reached 89,000/mm . He was stone-free after bilateral ureterorenoscopy and pneumatic lithotripsy. There was no increase in the size of the hematoma, and regression was even shown on the post- operative control CT scan (Fig. 3). The patient was dis- charged under prednisolone therapy with necessary recommendations. His control magnetic resonance imag- ing study showed regression of the perirenal hematoma (Fig. 4), and his blood urea nitrogen was 25 mg/dl and his creatinine was 0.79 mg/dl after 1 year. Korean J Urol 2012;53:502-504