Unusual histological findings in a child with idiopathic nephrotic syndrome

We report a 2-year-old child with corticosteroid-resistant nephrotic syndrome whose renal biopsy revealed light microscopically normal glomeruli but highly unusual finger-like projections and arches of the glomerular basement membrane. To our knowledge, the association between nephrotic syndrome and this patient's rare ultrastuctural lesion has not been previously documented in the literature. It is not certain whether this basement membrane is pathogenic or a striking but coincidental developmental anomaly.