A 25-year-old man without any prior comorbidities presented to the emergency department (ED) with acute-onset right-sided flank pain. He observed frothy urine a few weeks before the onset of flank pain but reported no history of fever or dysuria. Physical examination was unremarkable except for right flank tenderness and pedal edema. Blood pressure on admission was 135/80mm Hg. Laboratory results obtained at the ED visit are shown in Table 1. No previous serum creatinine values were available. A kidney ultrasound showed a right-sided bulky kidney without hydroureteronephrosis or calculus and a contrast-enhanced computed tomography (CECT) of the abdomen found a right renal vein and inferior vena cava thrombosis.