Adult Idiopathic Renal Vein Thrombosis Mimicking Acute Pyelonephritis

Renal Vein Thrombosis (RVT) is a rarely encountered condition. It occurs due to a hypercoagulable state in the body, caused by nephrotic syndrome and membranous nephropathy in the adults. Mode of presentation is variable. In chronic form, it may remain silent for a long time and presenting later with symptoms of pedal oedema, varicocele, proteinuria. In acute state, it manifests as flank pain, nausea or haematuria. We present a case of 25-year-old male, with left sided flank pain, haematuria and nausea for 4 days. Ultrasound showed enlarged kidney with altered echogenecity. No calculus was found on x-ray. Empirical antibiotics were started considering possibility of Acute Pyelonephritis (APN). With no improvement seen after 3 days along with no growth on urine culture, CT-urography was done. It revealed enlarged non-excreting left kidney with thrombus seen over left renal vein extending into Inferior Vena Cava (IVC). Immediate anticoagulant therapy was started. Patients recovered gradually and after 6 months, follow-up CT showed disappearance of thrombosis. Anticoagulants were withdrawn gradually. So we highlight the possibility of RVT as a differential diagnosis to APN or renal colic and its evaluation and management.