Kidney Function

Nephrotic syndrome is characterized by heavy proteinuria (protein excretion >3.5 g/24 h in adults or 40 mg/m2/h in children), hypoalbuminemia (albumin <2.5 g/dL), edema, and hyperlipidemia. Edema results from fluid accumulation in the subcutaneous tissue. Fluid also commonly accumulates in the peritoneal and pleural cavities. Rarely, fluid may accumulate in the subcapsular space around the kidneys. Such subcapsular fluid accumulation has been reported as a complication of nephrotic syndrome or in association with severe pulmonary hypertension. We describe a patient with nephrotic syndrome who presented with hypertension and pain in the left lumbar region. Ultrasonography and magnetic resonance imaging (MRI) showed a massive subcapsular collection around the left kidney. The patient was treated successfully with ultrasonography-guided drainage of the collection and medical treatment. The kidney biopsy specimen showed changes of focal segmental glomerulosclerosis.