Looking at appearance of urine before performing a renal biopsy in nephrotic syndrome.

Chyluria results from an abnormal connection between lymphatic bed and urinary tract, causing lymph leakage into the urine. The clinical picture often begins with the appearance of cloudy, milky urines accompanied by monolateral flank pain, malnutrition, weight loss and weakness. We report a case of chyluria that occurred in a young woman who was referred to our unit for nephrotic-range proteinuria. Before performing a renal biopsy, we found that urine analysis demonstrated a massive lipiduria. Therefore, we collected urine samples from each kidney with a selective ureteral catheterization, demonstrating a monolateral source of lipids and proteins. We suspended the renal biopsy and performed a lymphography that showed an inherited lymphangioma on the left lumbar lymphatic bed. Sclerosing solution instillation, renal pedicle lymphatic disconnection or laser therapy are invasive therapeutical options that may cause severe adverse effects. Instead of these procedures, a conservative therapy based on a low-fat diet supplemented with medium-chain triglycerides was chosen. This dietetic schedule was followed by complete resolution of proteinuria and lipiduria. The patient progressively gained body weight and improved quality of life. No relapses were observed after 3 years of follow-up. This case emphasizes the possible role of a noninvasive therapeutical option for patients with chyluria.