Chronic renal insufficiency in a boy with cystic renal lymphangiectasia: morphological findings and long-term follow-up.

Cystic renal lymphangiectasia (CRL) is a rare malformation of lymphatics that can present in childhood and adulthood. Symptoms and radiologic features are relatively well defined, but clinical evolution and prognosis remain unclear. We treated a boy with CRL who developed chronic renal insufficiency. The first manifestation was abdominal swelling associated with an umbilical hernia noted incidentally at 1.6 years. Computed tomography with intravenous contrast administration demonstrated perirenal cysts with fluid collection, suggesting CRL. Intractable ascites resisted pharmacologic treatments such as diuretics. After approximately 7 years, the ascites resolved spontaneously, but the perirenal cysts persisted. At 11 years, proteinuria was noted. A renal biopsy specimen showed interstitial abnormalities consistent with CRL, glomeruli showed a focal segmental mesangial increase. Proteinuria persisted despite administration of an angiotensin-converting enzyme inhibitor, increasing as obesity and hypertension worsened. Renal function gradually declined in the ensuing years. Polycythemia coexisted with a normal serum erythropoietin concentration. A follow-up renal biopsy specimen disclosed glomerular enlargement together with focal segmental mesangial expansion, suggesting obesity-related glomerulopathy. Our observation suggest that under some specific circumstances like our patient CRL may exacerbate. Management of complicating obesity and hypertension are likely to be important for maintaining normal renal function, especially in the diffuse bilateral type of CRL present in our patient.